net/smc: fix another sizeof to int comparison

Comparing an int to a size, which is unsigned, causes the int to become
unsigned, giving the wrong result. kernel_sendmsg can return a negative
error code.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/smc_clc.c

@@ -378,7 +378,7 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 	vec.iov_len = sizeof(struct smc_clc_msg_decline);
 	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 			     sizeof(struct smc_clc_msg_decline));
-	if (len < sizeof(struct smc_clc_msg_decline))
+	if (len < 0 || len < sizeof(struct smc_clc_msg_decline))
 		len = -EPROTO;
 	return len > 0 ? 0 : len;
 }