BBQ: Check if the buffer is already in the pending release queue before logging

As a workaround for lost release callbacks, we try to
release buffers in the submitted queue. If the buffer
was released previously but held in the pending release
queue, we would log incorrectly. This fixes the misleading
logs.

Test: presubmit
Test: logcat
Fixes: 255679881
Change-Id: I7e46f21f4c4fa1ee8c70e3ee8cd3f3665fe7442a