Keyguard should updateFingerprintListeningState when goingAway changes

The missing update call wasn't causing anything bad as far as I could
tell, but it's more correct to have this fixed

Fixes: 66455597

Test: keyguard/fingerprint still works as expected
Change-Id: I6f1fec9c9eac5845f2b9290a6406ad20ee9863a7