drivers/nfc/nfcwilink.c: use devm_kzalloc

devm_kzalloc allocates memory that is released when a driver detaches.
This patch uses devm_kzalloc for data that is allocated in the probe
function of a platform device and is only freed in the remove function.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: John W. Linville <linville@tuxdriver.com>