Use fingerid 0 when checking failed attempts.

It is valid to have finger id as Hex value which is not necessarily less than 0.
Always compare with finger id 0 to make sure we are not locking out user.

Bug: 22354158
Change-Id: I19ded12ae4ee335621fd278163c652fc154be6cf

services/core/java/com/android/server/fingerprint/FingerprintService.java

@@ -539,8 +539,8 @@ public class FingerprintService extends SystemService implements IBinder.DeathRe
                 }
             } else {
                 result = true; // client not listening
-            }
-            if (fpId <= 0) {
+	    }
+	    if (fpId == 0) {
                 FingerprintUtils.vibrateFingerprintError(getContext());
                 result |= handleFailedAttempt(this);
             } else {