net: fix some sparse errors

make C=2 CF="-D__CHECK_ENDIAN__" M=net

And fix flowi4_init_output() prototype for sport

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c
index 6fd4460..99b2596 100644
--- a/net/core/secure_seq.c
+++ b/net/core/secure_seq.c
@@ -46,7 +46,7 @@
 
 	memcpy(hash, saddr, 16);
 	for (i = 0; i < 4; i++)
-		secret[i] = net_secret[i] + daddr[i];
+		secret[i] = net_secret[i] + (__force u32)daddr[i];
 	secret[4] = net_secret[4] +
 		(((__force u16)sport << 16) + (__force u16)dport);
 	for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)