Create listen SCO for HS1 if HS2 disconnects during SCO xfer

During SCO transfer process from HS1 to HS2, firstly active SCO for
HS1 is disconnected. However, if suddenly HS2 disconnects even
before SCO transfer is complete, listen SCO for HS1 is not created.
This causes further incoming SCO connections from HS1 to be rejected.
The change creates listen SCO for HS1 and moves SCO state properly
to LISTEN.

Change-Id: I0993c1ba1c24b3b7e9c243d179a913d7a0c40446