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 <wsa+renesas@sang-engineering.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200316163907.13709-3-wsa+renesas@sang-engineering.com

drivers/gpu/drm/drm_encoder_slave.c

@@ -61,13 +61,8 @@ int drm_i2c_encoder_init(struct drm_device *dev,
 
 	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;
 	}
@@ -96,7 +91,6 @@ int drm_i2c_encoder_init(struct drm_device *dev,
 	module_put(module);
 fail_unregister:
 	i2c_unregister_device(client);
-fail:
 	return err;
 }
 EXPORT_SYMBOL(drm_i2c_encoder_init);