remove system-compiled binutils dirs from $LDFLAGS in binutils easyblock

[bartoldeman]

Various binutils binaries were linked with both libiberty from
binutils compiled with the system toolchain and libiberty from
binutils compiled with a compiler toolchain.

The gold linker allows this but ld.bfd does not, and it's not
a good thing to do in any case. Removing -L$EBROOTBINUTILS/lib*
from LDFLAGS fixes this issue.

edit (by @boegel): just to make this PR easy to find in case people hit the problem this is causing, here's the error message you get without this change (harvested from a test report in easybuilders/easybuild-easyconfigs#15311 (comment)):

/project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/bin/ld: ../libiberty/libiberty.a(concat.o): in function `concat_length':
concat.c:(.text+0x0): multiple definition of `concat_length'; /project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/lib64/libiberty.a(concat.o):/tmp/boegelbot/binutils/2.38/system-system/binutils-2.38/libiberty/./concat.c:91: first defined here
/project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/bin/ld: ../libiberty/libiberty.a(concat.o): in function `concat_copy':
concat.c:(.text+0xb0): multiple definition of `concat_copy'; /project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/lib64/libiberty.a(concat.o):/tmp/boegelbot/binutils/2.38/system-system/binutils-2.38/libiberty/./concat.c:106: first defined here
/project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/bin/ld: ../libiberty/libiberty.a(concat.o): in function `concat_copy2':
concat.c:(.text+0x190): multiple definition of `concat_copy2'; /project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/lib64/libiberty.a(concat.o):/tmp/boegelbot/binutils/2.38/system-system/binutils-2.38/libiberty/./concat.c:130: first defined here
/project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/bin/ld: ../libiberty/libiberty.a(concat.o): in function `concat':
concat.c:(.text+0x260): multiple definition of `concat'; /project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/lib64/libiberty.a(concat.o):/tmp/boegelbot/binutils/2.38/system-system/binutils-2.38/libiberty/./concat.c:141: first defined here
/project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/bin/ld: ../libiberty/libiberty.a(concat.o): in function `reconcat':
concat.c:(.text+0x3e0): multiple definition of `reconcat'; /project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/lib64/libiberty.a(concat.o):/tmp/boegelbot/binutils/2.38/system-system/binutils-2.38/libiberty/./concat.c:178: first defined here
/project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/bin/ld: ../libiberty/libiberty.a(xexit.o): in function `xexit':
xexit.c:(.text+0x0): multiple definition of `xexit'; /project/def-maintainers/boegelbot/Rocky8/zen2/software/binutils/2.38/lib64/libiberty.a(xexit.o):/tmp/boegelbot/binutils/2.38/system-system/binutils-2.38/libiberty/./xexit.c:48: first defined here
collect2: error: ld returned 1 exit status
make[4]: *** [Makefile:1049: readelf] Error 1

[casparvl]

Test report by @casparvl

Overview of tested easyconfigs (in order)

• SUCCESS GCCcore-10.3.0.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
tcn1.local.snellius.surf.nl - Linux RHEL 8.4, x86_64, AMD EPYC 7H12 64-Core Processor, Python 3.6.8
See https://gist.github.com/dd3a074240f8cba80ab723a4339551ee for a full test report.

[boegel]

Test report by @boegel

Overview of tested easyconfigs (in order)

• SUCCESS binutils-2.30-GCCcore-7.3.0.eb
• SUCCESS binutils-2.30.eb
• SUCCESS binutils-2.31.1.eb
• SUCCESS binutils-2.32-GCCcore-8.3.0.eb
• SUCCESS binutils-2.32.eb
• SUCCESS binutils-2.34-GCCcore-9.3.0.eb
• SUCCESS binutils-2.34.eb
• SUCCESS binutils-2.35-GCCcore-10.2.0.eb
• SUCCESS binutils-2.35.eb
• SUCCESS binutils-2.36.1-GCCcore-10.3.0.eb
• SUCCESS binutils-2.36.1.eb
• SUCCESS binutils-2.37-GCCcore-11.2.0.eb
• SUCCESS binutils-2.37.eb

Build succeeded for 13 out of 13 (13 easyconfigs in total)
node3519.doduo.os - Linux RHEL 8.4, x86_64, AMD EPYC 7552 48-Core Processor (zen2), Python 3.6.8
See https://gist.github.com/f909b3389382e44e6aba43e0e459c886 for a full test report.

[boegel]

Test report by @boegel

Overview of tested easyconfigs (in order)

• SUCCESS binutils-2.32-GCCcore-8.3.0.eb
• SUCCESS binutils-2.32.eb
• SUCCESS binutils-2.34-GCCcore-9.3.0.eb
• SUCCESS binutils-2.34.eb
• SUCCESS binutils-2.35-GCCcore-10.2.0.eb
• SUCCESS binutils-2.35.eb
• SUCCESS binutils-2.36.1-GCCcore-10.3.0.eb
• SUCCESS binutils-2.36.1.eb
• SUCCESS binutils-2.37-GCCcore-11.2.0.eb
• SUCCESS binutils-2.37.eb

Build succeeded for 10 out of 10 (10 easyconfigs in total)
node2613.swalot.os - Linux CentOS Linux 7.9.2009, x86_64, Intel(R) Xeon(R) CPU E5-2660 v3 @ 2.60GHz (haswell), Python 3.6.8
See https://gist.github.com/203360d16e24ac95b869d7b09452290e for a full test report.

[boegel]

lgtm