dlm: make tcp still work in multi-link env

[ Upstream commit 03d2b622 ]

This patch bypasses multi-link errors in TCP mode, allowing dlm
to operate on the first tcp link.

Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>