kcmp: include linux/ptrace.h

This makes it compile on s390. After all the ptrace_may_access
(which we use this file) is declared exactly in linux/ptrace.h.

This is preparatory work to wire this syscall up on all archs.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/kcmp.c b/kernel/kcmp.c
index 30b7b22..e30ac0f 100644
--- a/kernel/kcmp.c
+++ b/kernel/kcmp.c
@@ -4,6 +4,7 @@
 #include <linux/string.h>
 #include <linux/random.h>
 #include <linux/module.h>
+#include <linux/ptrace.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/cache.h>