media: i2c: imx334: Drop check for reentrant .s_stream()

The subdev .s_stream() operation shall not be called to start streaming
on an already started subdev, or stop streaming on a stopped subdev.
Remove the check that guards against that condition.

The streaming field of the driver's private structure is now unused,
drop it as well.

Signed-off-by: Laurent Pinchart <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/i2c/imx334.c

···
  * @mutex: Mutex for serializing sensor controls
  * @menu_skip_mask: Menu skip mask for link_freq_ctrl
  * @cur_code: current selected format code
- * @streaming: Flag indicating streaming state
  */
 struct imx334 {
 	struct device *dev;
···
 	struct mutex mutex;
 	unsigned long menu_skip_mask;
 	u32 cur_code;
-	bool streaming;
 };
 
 static const s64 link_freq[] = {
···
 
 	mutex_lock(&imx334->mutex);
 
-	if (imx334->streaming == enable) {
-		mutex_unlock(&imx334->mutex);
-		return 0;
-	}
-
 	if (enable) {
 		ret = pm_runtime_resume_and_get(imx334->dev);
 		if (ret < 0)
···
 		imx334_stop_streaming(imx334);
 		pm_runtime_put(imx334->dev);
 	}
-
-	imx334->streaming = enable;
 
 	mutex_unlock(&imx334->mutex);