NFC: nfcwilink: Drop a useless static qualifier

There is no need to have the 'struct nfcwilink *drv' variable static in the
probe function.
It only wastes a few bytes of memory.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>