Re-check device state after fpi_drvcb_enroll_stage_completed().
If enrollment was cancelled after non-completing stage, we must
not restart acquire as it would confuse the internal state machine.
https://bugs.freedesktop.org/show_bug.cgi?id=57829
Call error callback before resetting img_transfer to NULL. This
variable is internally used to detect if we are still in imaging
loop and the call to execute_state_change() needs to be postponed.
Since this is the final thing imaging_complete() we can't reset
img_transfer until just before this call.
https://bugs.freedesktop.org/show_bug.cgi?id=57829
It can come before we finish reading the status register on some
cases. Arm the irq handler early, and fix the state machine to
handle early irq properly.
https://bugs.freedesktop.org/show_bug.cgi?id=57834
