extmod/vfs_fat_diskio: Factor disk ioctl code to reduce code size.
extmod/vfs_fat_diskio: Factor disk ioctl code to reduce code size.

Functionality is unchanged.

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