vfs: trim includes a bit

[folded fix for missing magic.h from Tetsuo Handa]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 2cb5db5..80a09c3 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -5,6 +5,7 @@
  */
 
 #include "common.h"
+#include <linux/magic.h>
 
 /**
  * tomoyo_encode2 - Encode binary string to ascii string.