kcmp selftests: print fail status instead of cause make error

In case kcmp_test exit non zero value it will cause make error.
Better way is just print the test failure status.

Signed-off-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>