nvme_ctrlr_process_io_completions() and
nvme_ctrlr_process_admin_completions() now return the number of
completions processed.
This also adds the possibility of returning an error from the
process_*_completions functions (currently unused, but this at least
gets the API ready in case error conditions are added later).
Change-Id: I1b32ee4f2f3c1c474d646fa2d6b8b7bbb769785f
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
2ced60e9bf