libbinder: -case in 'Waiting for service' log.

This log used to distinguish between vendor and
system services, but I'm simplifying it here
to just print the devnode.

Bug: N/A
Test: boot device

(cherry picked from commit ef086dd8)
CRs-Fixed:2302602

Change-Id: Ie10042caf5d28c59e54a832a6bf7b140f6251265