Input: fix EVIOCSFF macro inconsistency by using _IOW()

Just like the EVIOCSABS(abs) macro, use the more compact
_IOW(..., type) instead of _IOC(_IOC_WRITE, ..., sizeof(type))
for the EVIOCSFF macro.

Signed-off-by: Elias Vanderstuyft <elias.vds@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>