udev-builtin-input_ic: simplify loop in test_key()

udev-builtin-input_ic: simplify loop in test_key()

We would update 'found' using bit operations, but studiously ignore the actual
value and treat it as boolean. So just use a boolean variable instead. Because
there is a double loop, we would break the inner loop, but repeat the outer
loop, even though the boolean was already set. Add '&& !found' in the loop
conditions to break iteration immediately.