extmod/modbluetooth: Unify error handling in remaining places.
extmod/modbluetooth: Unify error handling in remaining places.

Most error handling is done via `bluetooth_handle_errno()` already.
Replace the remaining few manual checks with calls to that function.

tobbad/micropython,bvernoux/micropython,pozetroninc/micropython,bvernoux/micropython,MrSurly/micropython,pozetroninc/micropython,pramasoul/micropython,bvernoux/micropython,bvernoux/micropython,pramasoul/micropython,pramasoul/micropython,MrSurly/micropython,pramasoul/micropython,selste/micropython,adafruit/circuitpython,kerneltask/micropython,selste/micropython,tobbad/micropython,pramasoul/micropython,adafruit/circuitpython,henriknelson/micropython,adafruit/circuitpython,adafruit/circuitpython,bvernoux/micropython,adafruit/circuitpython,henriknelson/micropython,henriknelson/micropython,tobbad/micropython,MrSurly/micropython,henriknelson/micropython,kerneltask/micropython,kerneltask/micropython,pozetroninc/micropython,adafruit/circuitpython,MrSurly/micropython,tobbad/micropython,selste/micropython,tobbad/micropython,selste/micropython,henriknelson/micropython,selste/micropython,kerneltask/micropython,pozetroninc/micropython,MrSurly/micropython,kerneltask/micropython,pozetroninc/micropython