glibc: Fix multilibs + usrmerge builds

glibc: Fix multilibs + usrmerge builds

The build of glibc fails when you have multilibs enabled + the distro
feature usrmerge.  Here is an example configuration:

===
MACHINE = "qemux86-64"
VIRTUAL-RUNTIME_init_manager = "systemd"
DISTRO_FEATURES_append = " systemd "
DISTRO_FEATURES_append += " usrmerge"

require conf/multilib.conf
MULTILIBS = "multilib:lib32"
DEFAULTTUNE_virtclass-multilib-lib32 = "x86"
===

This will fail with the following error:

NOTE: Executing SetScene Tasks
NOTE: Executing RunQueue Tasks
ERROR: glibc-2.28-r0 do_poststash_install_cleanup: Function failed: do_poststash_install_cleanup (log file is located at /poky/build/tmp/work/core2-64-poky-linux/glibc/2.28-r0/temp/log.do_poststash_install_cleanup.107893)
ERROR: Logfile of failure stored in: /poky/build/tmp/work/core2-64-poky-linux/glibc/2.28-r0/temp/log.do_poststash_install_cleanup.107893

The fix is to not perform the rmdir check when using the multilib + usr/merge, namely:

if [ "${libdir}" != "${exec_prefix}/lib" ] && [ "${root_prefix}/lib" != "${exec_prefix}/lib" ]; then

This will evaluate as follows (collecting the output from bitbake -e glibc)

* no multilibs no usrmerge
        if [ "/usr/lib" != "/usr/lib" ] && [ "/lib" != "/usr/lib" ]; then
* no multilibs yes usrmerge
        if [ "/usr/lib" != "/usr/lib" ] && [ "/usr/lib" != "/usr/lib" ]; then
* yes multilibs no usrmerge
        if [ "/usr/lib64" != "/usr/lib" ] && [ "/lib" != "/usr/lib" ]; then
* yes multilibs yes user merge
        if [ "/usr/lib64" != "/usr/lib" ] && [ "/usr/lib" != "/usr/lib" ]; then

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>