media: i2c: imx219: simplify getting state container

The pointer to 'struct v4l2_subdev' is stored in drvdata via
v4l2_i2c_subdev_init() so there is no point of a dance like:

    struct i2c_client *client = to_i2c_client(struct device *dev)
    struct v4l2_subdev *sd = i2c_get_clientdata(client);

This allows to remove local variable 'client' and few pointer
dereferences.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/i2c/imx219.c

@@ -1114,22 +1114,21 @@ static int imx219_set_stream(struct v4l2_subdev *sd, int enable)
 /* Power/clock management functions */
 static int imx219_power_on(struct device *dev)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct imx219 *imx219 = to_imx219(sd);
 	int ret;
 
 	ret = regulator_bulk_enable(IMX219_NUM_SUPPLIES,
 				    imx219->supplies);
 	if (ret) {
-		dev_err(&client->dev, "%s: failed to enable regulators\n",
+		dev_err(dev, "%s: failed to enable regulators\n",
 			__func__);
 		return ret;
 	}
 
 	ret = clk_prepare_enable(imx219->xclk);
 	if (ret) {
-		dev_err(&client->dev, "%s: failed to enable clock\n",
+		dev_err(dev, "%s: failed to enable clock\n",
 			__func__);
 		goto reg_off;
 	}
@@ -1148,8 +1147,7 @@ static int imx219_power_on(struct device *dev)
 
 static int imx219_power_off(struct device *dev)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct imx219 *imx219 = to_imx219(sd);
 
 	gpiod_set_value_cansleep(imx219->reset_gpio, 0);
@@ -1161,8 +1159,7 @@ static int imx219_power_off(struct device *dev)
 
 static int __maybe_unused imx219_suspend(struct device *dev)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct imx219 *imx219 = to_imx219(sd);
 
 	if (imx219->streaming)
@@ -1173,8 +1170,7 @@ static int __maybe_unused imx219_suspend(struct device *dev)
 
 static int __maybe_unused imx219_resume(struct device *dev)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct imx219 *imx219 = to_imx219(sd);
 	int ret;