Refactor A2DP finalize_*_errno functions
Refactor A2DP finalize_*_errno functions

There was a lot of duplicate code in them so they are now replaced by
finalize_setup_errno which can deal with multiple callbacks reusing the
same error.

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