Fixup post-/usr: need /usr/lib64

[MilhouseVH]

After #805 (merge /usr), we need a /usr/lib64 sym link.

NUC:~ # lsb_release
LibreELEC (Milhouse) - Version: devel-20161214021654-#1213x-g4b0e759 [Build #1213x]
NUC:~ # ls -la /usr/bin/Xorg
-rwxr-xr-x    1 root     root       1893088 Dec 14 02:18 /usr/bin/Xorg
NUC:~ # ldd /usr/bin/Xorg
$       not a dynamic executable

@escalade

9:41 AM you'll get not a dynamic executable
9:41strace shows ldd looking for /usr/lib/ld-linux.so.2, which isn't there then /usr/lib64/ld-linux-x86-64.so.2 which isn't there either
9:41there's /usr/lib/ld-linux-x86-64.so.2
9:42 in my build i symlinked /usr/lib to /usr/lib64 and it works

/usr/bin/ldd before /usr:

RTLDLIST="/lib/ld-linux.so.2 /lib64/ld-linux-x86-64.so.2 /libx32/ld-linux-x32.so.2"

/usr/bin/ldd AFTER /usr:

RTLDLIST="/usr/lib/ld-linux.so.2 /usr/lib64/ld-linux-x86-64.so.2 /usr/libx32/ld-linux-x32.so.2"

We only have /lib64 sym link, while /usr/lib64 is missing.

Not entirely sure if the /usr/lib64 sym link in initrd is required - haven't had time to investigate that but guess it does no harm. Quickly run-time tested and system boots, ldd works again.

[MilhouseVH]

Changing RTLDLIST in /usr/bin/ldd so that it references /lib64 rather than /usr/lib64 might be an alternative solution, assuming it is only /usr/bin/ldd that now references /usr/lib64...