fbdev: via: Fix error in via_core_init()

via_core_init() won't exit the driver when pci_register_driver() failed.
Exit the viafb-i2c and the viafb-gpio in failed path to prevent error.

VIA Graphics Integration Chipset framebuffer 2.4 initializing
Error: Driver 'viafb-i2c' is already registered, aborting...
Error: Driver 'viafb-gpio' is already registered, aborting...

Fixes: 7582eb9be85f ("viafb: Turn GPIO and i2c into proper platform devices")
Signed-off-by: Shang XiaoJing <[e-mail]>
Signed-off-by: Helge Deller <[e-mail]>

drivers/video/fbdev/via/via-core.c

···
 		return ret;
 	viafb_i2c_init();
 	viafb_gpio_init();
-	return pci_register_driver(&via_driver);
+	ret = pci_register_driver(&via_driver);
+	if (ret) {
+		viafb_gpio_exit();
+		viafb_i2c_exit();
+		return ret;
+	}
+
+	return 0;
 }
 
 static void __exit via_core_exit(void)