captouch: bring back redundant calibration

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