Don't bail out if Discovery is in progress when getting the rfcomm channel.

Don't bail out if Discovery is in progress when getting the rfcomm channel.

We should be having the SDP record in the cache. In the very rare
case, that the remote device's SDP records have changed and if a discovery
is in progress, we would have already updated the cache or if we have not
queried the device yet, we are going to fail anyways.