efifb: Fix call to wrong unregister function

platform_device_unregister() needs to unregister the device, not the
driver.

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Acked-by: Andy Lutomirski <luto@mit.edu>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/video/efifb.c

@@ -541,7 +541,7 @@ static int __init efifb_init(void)
 	 */
 	ret = platform_driver_probe(&efifb_driver, efifb_probe);
 	if (ret) {
-		platform_device_unregister(&efifb_driver);
+		platform_device_unregister(&efifb_device);
 		return ret;
 	}