xfrm: simplify xfrm_address_t use

In many places, the a6 field is typecasted to struct in6_addr. As the
fields are in union anyway, just add in6_addr type to the union and
get rid of the typecasting.

Modifying the uapi header is okay, the union has still the same size.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index 02d5125..2cd9e60 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -1,6 +1,7 @@
 #ifndef _LINUX_XFRM_H
 #define _LINUX_XFRM_H
 
+#include <linux/in6.h>
 #include <linux/types.h>
 
 /* All of the structures in this file may not change size as they are
@@ -13,6 +14,7 @@
 typedef union {
 	__be32		a4;
 	__be32		a6[4];
+	struct in6_addr	in6;
 } xfrm_address_t;
 
 /* Ident of a specific xfrm_state. It is used on input to lookup