rt2x00: Remove redundant code in rfkill setup

In rt2x00rfkill.c, routine input_allocate_device() is called even though
input_allocate_polled_device(), which was just called, includes a call to
that routine. This patch, which has not been tested, removes the redundant code.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>