media: i2c: adv748x: Use devm to allocate the device struct

Switch to devm_kzalloc() when allocating the adv748x device struct.

The sizeof() is updated to determine the correct allocation size from
the dereferenced pointer type rather than hardcoding the struct type.

[Kieran: Change sizeof() to dereference the pointer type]
Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/i2c/adv748x/adv748x-core.c

@@ -631,7 +631,7 @@ static int adv748x_probe(struct i2c_client *client,
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 		return -EIO;
 
-	state = kzalloc(sizeof(struct adv748x_state), GFP_KERNEL);
+	state = devm_kzalloc(&client->dev, sizeof(*state), GFP_KERNEL);
 	if (!state)
 		return -ENOMEM;
 
@@ -729,7 +729,6 @@ static int adv748x_probe(struct i2c_client *client,
 	adv748x_dt_cleanup(state);
 err_free_mutex:
 	mutex_destroy(&state->mutex);
-	kfree(state);
 
 	return ret;
 }
@@ -748,8 +747,6 @@ static int adv748x_remove(struct i2c_client *client)
 	adv748x_dt_cleanup(state);
 	mutex_destroy(&state->mutex);
 
-	kfree(state);
-
 	return 0;
 }