fs: dlm: remove filter local comms on close

The current way how lowcomms is configured is due configfs entries. Each
comms configfs entry will create a lowcomms connection. Even the local
connection itself will be stored as a lowcomms connection, although most
functionality for a local lowcomms connection struct is not necessary.

Now in some scenarios we will see that dlm_controld reports a -EEXIST
when configure a node via configfs:

... /sys/kernel/config/dlm/cluster/comms/1/addr: write failed: 17 -1

Doing a:

cat /sys/kernel/config/dlm/cluster/comms/1/addr_list

reported nothing. This was being seen on cluster with nodeid 1 and it's
local configuration. To be sure the configfs entries are in sync with
lowcomms connection structures we always call dlm_midcomms_close() to be
sure the lowcomms connection gets removed when the configfs entry gets
dropped.

Before commit 07ee3867 ("fs: dlm: filter ourself midcomms calls") it
was just doing this by accident and the filter by doing:

if (nodeid == dlm_our_nodeid())
	return 0;

inside dlm_midcomms_close() was never been hit because drop_comm() sets
local_comm to NULL and cause that dlm_our_nodeid() returns always the
invalid nodeid 0.

Fixes: 07ee3867 ("fs: dlm: filter ourself midcomms calls")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>