Input: mainstone-wm97xx - fix condition in pen_up

The loop body was never executed, because the condition is
always false. Convert to for with more obvious condition.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/mainstone-wm97xx.c

@@ -111,13 +111,12 @@ static void wm97xx_acc_pen_up(struct wm97xx *wm)
 #else
 static void wm97xx_acc_pen_up(struct wm97xx *wm)
 {
-	int count = 16;
+	unsigned int count;
+
 	schedule_timeout_uninterruptible(1);
 
-	while (count < 16) {
+	for (count = 0; count < 16; count++)
 		MODR;
-		count--;
-	}
 }
 #endif