acer-wmi: double free in acer_rfkill_exit()

This is acer_rfkill_exit() from drivers/platform/x86/acer-wmi.c.

The code frees wireless_rfkill->data again instead of
bluetooth_rfkill->data.

This was found using a code checker (http://repo.or.cz/w/smatch.git/).
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/platform/x86/acer-wmi.c

@@ -1026,7 +1026,7 @@ static void acer_rfkill_exit(void)
 	kfree(wireless_rfkill->data);
 	rfkill_unregister(wireless_rfkill);
 	if (has_cap(ACER_CAP_BLUETOOTH)) {
-		kfree(wireless_rfkill->data);
+		kfree(bluetooth_rfkill->data);
 		rfkill_unregister(bluetooth_rfkill);
 	}
 	return;