[IPV4]: fib_validate_source() annotations

annotated arguments and inferred net-endian variables in callers

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 9d8fbf1..4bb66fe 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1722,7 +1722,8 @@
 	int err;
 	struct in_device *out_dev;
 	unsigned flags = 0;
-	u32 spec_dst, itag;
+	__be32 spec_dst;
+	u32 itag;
 
 	/* get a working reference to the output device */
 	out_dev = in_dev_get(FIB_RES_DEV(*res));