elf: Remove version assert in check_match in elf/dl-lookup.c

elf: Remove version assert in check_match in elf/dl-lookup.c

This case is detected early in the elf/dl-version.c consistency
checks.  (These checks could be disabled in the future to allow
the removal of symbol versioning from objects.)

Commit f0b2132b35 ("ld.so: Support moving versioned symbols between
sonames [BZ #24741]) removed another call to _dl_name_match_p.  The
_dl_check_caller function no longer exists, and the remaining calls
to _dl_name_match_p happen under the loader lock.  This means that
atomic accesses are no longer required for the l_libname list.  This
supersedes commit 395be7c218 ("elf: Fix data race in _dl_name_match_p
[BZ #21349]").