HID: pidff: effect can't be NULL

Force-beedback core guarantees that the 'effect' pointer that's being passed
to ->upload() callback is non-NULL.

Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: Jiri Kosina <[e-mail]>

drivers/hid/usbhid/hid-pidff.c

···
 	int error;
 
 	pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] = 0;
-	if (old && effect) {
+	if (old) {
 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] =
 			pidff->pid_id[effect->id];
 	}