keys: explicitly include required slab.h header file.

Since these two source files invoke kmalloc(), they should explicitly
include <linux/slab.h>.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security/keys/request_key.c

@@ -16,6 +16,7 @@
 #include <linux/kmod.h>
 #include <linux/err.h>
 #include <linux/keyctl.h>
+#include <linux/slab.h>
 #include "internal.h"
 
 /*

security/keys/request_key_auth.c

@@ -15,6 +15,7 @@
 #include <linux/sched.h>
 #include <linux/err.h>
 #include <linux/seq_file.h>
+#include <linux/slab.h>
 #include <asm/uaccess.h>
 #include "internal.h"