NFC: pn533: Fix use after free

cmd was freed in pn533_dep_link_up regardless of
pn533_send_cmd_frame_async return code. Cmd is passed as argument to
pn533_in_dep_link_up_complete callback and should be freed there.

Signed-off-by: Szymon Janc <szymon.janc@tieto.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>