unix_diag: Include unix_diag.h into header-y target

The headers check complains it should include the linux/types.h
withing, thus add this one.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/unix_diag.h b/include/linux/unix_diag.h
index 3f7afb0..a5ce0f3 100644
--- a/include/linux/unix_diag.h
+++ b/include/linux/unix_diag.h
@@ -1,6 +1,8 @@
 #ifndef __UNIX_DIAG_H__
 #define __UNIX_DIAG_H__
 
+#include <linux/types.h>
+
 struct unix_diag_req {
 	__u8	sdiag_family;
 	__u8	sdiag_protocol;