selinux: include vmalloc.h for vmalloc_user

Include vmalloc.h for vmalloc_user (fixes ppc build warning).
Acked-by: Eric Paris <eparis@redhat.com>

Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 3a1739b..223c1ff 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -51,6 +51,7 @@
 #include <linux/mutex.h>
 #include <linux/selinux.h>
 #include <linux/flex_array.h>
+#include <linux/vmalloc.h>
 #include <net/netlabel.h>
 
 #include "flask.h"