Input: psmouse - fix compile warning in hgpk module

The variable 'dev' is unused in function 'hgpk_register'.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/mouse/hgpk.c

@@ -427,7 +427,6 @@ static void hgpk_recalib_work(struct work_struct *work)
 
 static int hgpk_register(struct psmouse *psmouse)
 {
-	struct input_dev *dev = psmouse->dev;
 	int err;
 
 	/* register handlers */