obexd/client/map: Check msg value is valid
obexd/client/map: Check msg value is valid

Checks for NULL value before passing to the callback.

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