media: Fix leaking endpoint in case of failure to register SEP
media: Fix leaking endpoint in case of failure to register SEP

This can happen in case of AudioSink and/or AudioSource are disabled in
audio.conf.

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