core: Fix not forwarding errors caused by SDP search properly
core: Fix not forwarding errors caused by SDP search properly

In case bt_search_service fails while processing (e.g. connection is
dropped) the error forward is a positive value leading
btd_service_connecting_complete to not change any state at all.

Futhermore the error from sdp_process was completely ignored which may
cause problems as well.

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