For old glibc there's no the syscall number this tests will cause
make run_tests fail.
Add a macro to define the number. This should be ok because it will be
built in latest kernel source.

Signed-off-by: Dave Young <dyoung@redhat.com>
---
 tools/testing/selftests/kcmp/kcmp_test.c |    3 +++
 1 file changed, 3 insertions(+)

--- linux-2.6.orig/tools/testing/selftests/kcmp/kcmp_test.c	2012-11-23 22:37:04.789058192 +0800
+++ linux-2.6/tools/testing/selftests/kcmp/kcmp_test.c	2012-11-23 22:38:43.195191747 +0800
@@ -17,6 +17,9 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 
+#ifndef __NR_kcmp
+#define __NR_kcmp 272
+#endif
 static long sys_kcmp(int pid1, int pid2, int type, int fd1, int fd2)
 {
 	return syscall(__NR_kcmp, pid1, pid2, type, fd1, fd2);