py/stream: Update comment for mp_stream_write_adaptor.
py/stream: Update comment for mp_stream_write_adaptor.

pfalcon/micropython,tobbad/micropython,selste/micropython,selste/micropython,kerneltask/micropython,MrSurly/micropython,MrSurly/micropython,adafruit/circuitpython,trezor/micropython,bvernoux/micropython,selste/micropython,swegener/micropython,adafruit/micropython,pozetroninc/micropython,swegener/micropython,pramasoul/micropython,tralamazza/micropython,pramasoul/micropython,pramasoul/micropython,trezor/micropython,pozetroninc/micropython,pramasoul/micropython,trezor/micropython,henriknelson/micropython,adafruit/circuitpython,tobbad/micropython,swegener/micropython,adafruit/micropython,adafruit/circuitpython,henriknelson/micropython,pfalcon/micropython,swegener/micropython,adafruit/micropython,trezor/micropython,kerneltask/micropython,selste/micropython,bvernoux/micropython,adafruit/micropython,bvernoux/micropython,MrSurly/micropython,adafruit/circuitpython,tralamazza/micropython,bvernoux/micropython,adafruit/micropython,swegener/micropython,henriknelson/micropython,tobbad/micropython,tobbad/micropython,MrSurly/micropython,tralamazza/micropython,henriknelson/micropython,bvernoux/micropython,tralamazza/micropython,pozetroninc/micropython,adafruit/circuitpython,kerneltask/micropython,kerneltask/micropython,MrSurly/micropython,trezor/micropython,pfalcon/micropython,kerneltask/micropython,pfalcon/micropython,henriknelson/micropython,tobbad/micropython,adafruit/circuitpython,pfalcon/micropython,pramasoul/micropython,pozetroninc/micropython,pozetroninc/micropython,selste/micropython