android/avctp: Fix crashes caused by re-entrant calls
android/avctp: Fix crashes caused by re-entrant calls

This make sure that while processing a PDU the session callbacks are
not able to destroy the session causing crashes.

pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,mapfau/bluez,pkarasev3/bluez,ComputeCycles/bluez,ComputeCycles/bluez,silent-snowman/bluez,pkarasev3/bluez,mapfau/bluez,ComputeCycles/bluez,ComputeCycles/bluez,silent-snowman/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,pkarasev3/bluez