we're already changing a bunch, this one looks silly but it does
affect how user interaction affects calibration at boot. also file
access does weird stuff in general, maybe it does weird stuff to
captouch output too, so an early exit when called from mp is maybe
beneficial.

there's many cleaner ways to do this but we intentionally just go
back to 1.2 status quo to account for any wonk that might be at the
bottom of recently reported boot calib failures. we'll move to
persistent calib soon anyways, no reason to go out of our way here :P