RDS: restore return value in rds_cmsg_rdma_args()

In rds_cmsg_rdma_args() 'ret' is used by rds_pin_pages() which returns
number of pinned pages on success. And the same value is returned to the
caller of rds_cmsg_rdma_args() on success which is not intended.

Commit f4a3fc03 ("RDS: Clean up error handling in rds_cmsg_rdma_args")
removed the 'ret = 0' line which broke RDS RDMA mode.

Fix it by restoring the return value on rds_pin_pages() success
keeping the clean-up in place.
Signed-off-by: NSantosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/rds/rdma.c

@@ -658,6 +658,8 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
 		ret = rds_pin_pages(iov->addr, nr, pages, !op->op_write);
 		if (ret < 0)
 			goto out;
+		else
+			ret = 0;
 
 		rdsdebug("RDS: nr_bytes %u nr %u iov->bytes %llu iov->addr %llx\n",
 			 nr_bytes, nr, iov->bytes, iov->addr);