Failing fortran_dynamic_loader test

[nncarlson]

test_fortran_dynamic_loader is now failing on some platforms with the error

SHLIB:OPEN: /lib64/libm.so: invalid ELF header

In these cases It turns out that the .so file is not actually a library but a 'linker script' text file. I guess the linker knows how to deal with these, but the system dynamic loader function (dlopen) does not.

The unit test already includes tests that load a shared library built as part of the test, so the solution is probably just to delete the one test that loads /lib64/libm.so, which was a little iffy in the first place.