shared/gatt-helpers: Fix reporting discovery failure
shared/gatt-helpers: Fix reporting discovery failure

If sending ATT request failed discovery should be reported as failed.
Due to missing goto success was overwritten with true value.
This regression was introduced in db24bf09d66325a.

pkarasev3/bluez,pkarasev3/bluez,pkarasev3/bluez,pkarasev3/bluez