rds: Remove IPv6 dependency

This patch removes the IPv6 dependency from RDS.

Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/send.c b/net/rds/send.c
index 18e2b4d..36a5dba 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -1103,6 +1103,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 			dport = usin->sin_port;
 			break;
 
+#if IS_ENABLED(CONFIG_IPV6)
 		case AF_INET6: {
 			int addr_type;
 
@@ -1142,6 +1143,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 			dport = sin6->sin6_port;
 			break;
 		}
+#endif
 
 		default:
 			ret = -EINVAL;