'params' arg in pn533_cmd_complete_t definition has been deprecated and
currently is not in use (resp skb is pass in arg ptr), so remove it.

Also 'params_len' arg is used as a transfer status indicator, so simply
reword it appropriately.
Signed-off-by: NWaldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>