drm: encoder_slave: use new I2C API

i2c_new_client() is deprecated, use the replacement
i2c_new_client_device(). Also, we have a helper to check if a driver is
bound. Use it to simplify the code. Note that this changes the errno for
a failed device creation from ENOMEM to ENODEV. No callers currently
interpret this errno, though, so we use this condensed error check.

Signed-off-by: Wolfram Sang <[e-mail]>
Reviewed-by: Emil Velikov <[e-mail]>
Acked-by: Daniel Vetter <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

drivers/gpu/drm/drm_encoder_slave.c

···
 
 	request_module("%s%s", I2C_MODULE_PREFIX, info->type);
 
-	client = i2c_new_device(adap, info);
-	if (!client) {
-		err = -ENOMEM;
-		goto fail;
-	}
-
-	if (!client->dev.driver) {
+	client = i2c_new_client_device(adap, info);
+	if (!i2c_client_has_driver(client)) {
 		err = -ENODEV;
 		goto fail_unregister;
 	}
···
 	module_put(module);
 fail_unregister:
 	i2c_unregister_device(client);
-fail:
 	return err;
 }
 EXPORT_SYMBOL(drm_i2c_encoder_init);