net/smc: fix error return code in smc_setsockopt()

Fix to return error code -EINVAL instead of 0 if optlen is invalid.

Fixes: 01d2f7e2 ("net/smc: sockopts TCP_NODELAY and TCP_CORK")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/smc/af_smc.c

@@ -1420,7 +1420,7 @@ static int smc_setsockopt(struct socket *sock, int level, int optname,
 		return rc;
 
 	if (optlen < sizeof(int))
-		return rc;
+		return -EINVAL;
 	get_user(val, (int __user *)optval);
 
 	lock_sock(sk);