movement: fix unintended timeout short circuiting

movement: fix unintended timeout short circuiting

Currently, movement drops time out events in case the previous loop
indicates that sleep is not possible due to short circuiting behavior
of logical and in C: if the left-hand side is false, the right hand
side is not evaluated at all, which means the loop is not called.
This was not intended to happen.

Fix it by storing the result in a second boolean variable
and working out the logic after the fact.