net/rds: Drop duplicate sin and sin6 assignments

There is no need to assign the msg->msg_name to sin or sin6,
because there is DECLARE_SOCKADDR statement.

Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds/recv.c

@@ -722,17 +722,13 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 
 		if (msg->msg_name) {
 			if (ipv6_addr_v4mapped(&inc->i_saddr)) {
-				sin = (struct sockaddr_in *)msg->msg_name;
-
 				sin->sin_family = AF_INET;
 				sin->sin_port = inc->i_hdr.h_sport;
 				sin->sin_addr.s_addr =
 				    inc->i_saddr.s6_addr32[3];
 				memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 				msg->msg_namelen = sizeof(*sin);
 			} else {
-				sin6 = (struct sockaddr_in6 *)msg->msg_name;
-
 				sin6->sin6_family = AF_INET6;
 				sin6->sin6_port = inc->i_hdr.h_sport;
 				sin6->sin6_addr = inc->i_saddr;