dapl: endpoint pending request count is wrong

dapl: endpoint pending request count is wrong

The code assumes every cookie allocated during posting of
requests gets completed. This incorrect assumption results in
wrong pending count. Remove request_pending field and replace
with direct call, dapl_cb_pending, to provide accurate
data to consumer.

Add debug print if consumer overruns request queue.

Signed-off by: Arlin Davis ardavis@ichips.intel.com