fs: dlm: move connect callback in node creation

This patch moves the assignment for the connect callback to the node
creation instead of assign some dummy functionality. The assignment
which connect functionality will be used will be detected according to
the configfs setting.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>