selftests/mm: dont run ksm_functional_tests twice

ksm functional test is already being run.  Remove the duplicate call to
./ksm_functional_tests.

Link: https://lkml.kernel.org/r/20231129221140.614713-1-npache@redhat.com


Fixes: 93fb70aa ("selftests/vm: add KSM unmerge tests")
Signed-off-by: Nico Pache <npache@redhat.com>
Acked-by: Joel Savitz <jsavitz@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>