staging: most: video: Make use of the helper macro LIST_HEAD()

Replace "struct list_head head = LIST_HEAD_INIT(head)" with
"LIST_HEAD(head)" to simplify the code.
Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev>
Link: https://lore.kernel.org/r/20220209032715.38437-1-cai.huoqing@linux.devSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/most/video/video.c

@@ -52,7 +52,7 @@ struct comp_fh {
 	u32 offs;
 };
 
-static struct list_head video_devices = LIST_HEAD_INIT(video_devices);
+static LIST_HEAD(video_devices);
 static DEFINE_SPINLOCK(list_lock);
 
 static inline bool data_ready(struct most_video_dev *mdev)