mptcp: avoid error message on infinite mapping

Another left-over. Avoid flooding dmesg with useless text,
we already have a MIB for that event.

Fixes: 648ef4b8 ("mptcp: Implement MPTCP receive path")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/mptcp/subflow.c

@@ -867,7 +867,6 @@ static enum mapping_status get_mapping_status(struct sock *ssk,
 
 	data_len = mpext->data_len;
 	if (data_len == 0) {
-		pr_err("Infinite mapping not handled");
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX);
 		return MAPPING_INVALID;
 	}