NFC: pn533: Fix memleak while scheduling next cmd

In case of error from __pn533_send_frame_async() while sending
next cmd from the queue (cmd_wq), cmd->req, cmd->resp and
cmd->arg pointers won't be freed.

Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>