Input: fix potential overflows in driver/input/joystick

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/joystick/guillemot.c b/drivers/input/joystick/guillemot.c
index 6e2c721..840ed9b 100644
--- a/drivers/input/joystick/guillemot.c
+++ b/drivers/input/joystick/guillemot.c
@@ -222,7 +222,7 @@
 	gameport_set_poll_handler(gameport, guillemot_poll);
 	gameport_set_poll_interval(gameport, 20);
 
-	sprintf(guillemot->phys, "%s/input0", gameport->phys);
+	snprintf(guillemot->phys, sizeof(guillemot->phys), "%s/input0", gameport->phys);
 	guillemot->type = guillemot_type + i;
 
 	input_dev->name = guillemot_type[i].name;