cfm: Don't report unexpected remote endpoints.

cfm: Don't report unexpected remote endpoints.

Before this patch, CFM would report unexpected remote maintenance
points in the database.  This commit no longer exposes this
information.

Information about precisely why a link is faulty is more interesting
to a system administrator debugging a problem than a controller
which will generally only care about whether or not a link is
faulty.  For simplicity sake, this commit removes this information
from the database where it was somewhat awkwardly placed.  In the
future it may be valuable to report the information through
ovs-appctl commands for debugging purposes.