net: return operator cleanup

Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index fe6d404..8d93f6d 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -139,7 +139,7 @@
 		return -EINVAL;
 
 	if (usin->sin6_family != AF_INET6)
-		return(-EAFNOSUPPORT);
+		return -EAFNOSUPPORT;
 
 	memset(&fl, 0, sizeof(fl));