Fixes from PR feedback: Test DISABLE_FILESYSTEM after it set.
Fixes from PR feedback: Test DISABLE_FILESYSTEM after it set.

https://github.com/adafruit/circuitpython/pull/6492/files/53f4eeaf8b2a99da2562faa9828f3e80c4871800#r899419987
adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython