rconn: Preserve the name of an unreliable connection beyond disconnection.

rconn: Preserve the name of an unreliable connection beyond disconnection.

An rconn has a human-readable name that typically designates both endpoints
of the connection.  For a "reliable" rconn, that automatically reconnects,
the name remains constant regardless of whether the rconn is currently
connected.  Until now, though, an "unreliable" rconn, that cannot
automatically reconnect, kept its name only until disconnection occurred.
This is OK for the uses currently in the OVS tree, which only use the name
of a rconn while it is connected, but an upcoming commit will add a final
log message following disconnection in some cases, and it makes the log
messages less useful if unreliable rconns just report "void" in that case.
This commit, therefore, modifies the rconn code so that unreliable rconns
preserve their names past disconnection, just like reliable ones.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Alex Wang <alexw@nicira.com>