Input: fix potential overflows in driver/input/touchscreen

Change all sprintfs into snprintfs to make sure we won't stomp on
data adjacent to our buffers.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/gunze.c b/drivers/input/touchscreen/gunze.c
index 466da19..b769b21 100644
--- a/drivers/input/touchscreen/gunze.c
+++ b/drivers/input/touchscreen/gunze.c
@@ -129,7 +129,7 @@
 
 	gunze->serio = serio;
 	gunze->dev = input_dev;
-	sprintf(gunze->phys, "%s/input0", serio->phys);
+	snprintf(gunze->phys, sizeof(serio->phys), "%s/input0", serio->phys);
 
 	input_dev->private = gunze;
 	input_dev->name = "Gunze AHL-51S TouchScreen";