Fix typo.

a typo fix, forgot NULL in tst_brkm. And seems tst_resm+tst_exit could
be replaced by tst_brkm().

Signed-off-by: Caspar Zhang <czhang@redhat.com>
diff --git a/testcases/kernel/mem/mbind/mbind01.c b/testcases/kernel/mem/mbind/mbind01.c
index 9d99873..fc97174 100644
--- a/testcases/kernel/mem/mbind/mbind01.c
+++ b/testcases/kernel/mem/mbind/mbind01.c
@@ -142,13 +142,11 @@
 }
 #else /* libnuma v1 */
 int main(void) {
-	tst_brkm(TCONF, "XXX: test is only supported on libnuma v2.");
-	tst_exit();
+	tst_brkm(TCONF, NULL, "XXX: test is only supported on libnuma v2.");
 }
 #endif
 #else /* no NUMA */
 int main(void) {
-	tst_resm(TCONF, "no NUMA development packages installed.");
-	tst_exit();
+	tst_brkm(TCONF, NULL, "no NUMA development packages installed.");
 }
 #endif