[Bug 1189028] docker fd leak

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1189028

--- Comment #11 from Daniel Walsh  ---
There is no unregistermachine.  I don't see a nice way to call conn.Close.  I
have changed the code to only do conn.InitConnection once, which will at least
only open one descriptor for all of the daemon run.