msm: vidc: Don't print message queues in error cases

While flushing debug queues, avoid touching message queues.
Bleeding message queues here can discard FW responses and
forward threads may timeout by not receiving them. This can
cause confusion about timeouts. Hence don't touch message
queues unless you process and send them to forward thread.

CRs-Fixed: 1066658
Change-Id: I7a5a89c32dc4b1284895d01202dcfdd8a90ccda0
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>