media: v4l2-fh: define v4l2_fh struct regardless of condition

v4l2_fh struct define differently by CONFIG_V4L2_MEM2MEM_DEV.
If some vendors use CONFIG_V4L2_MEM2MEM_DEV by module,
it can make the mismatch of v4l2_fh sturct.

By the mismatch, the following error occurs.
===============================
[    7.533506] v4l2_mem2mem: disagrees about version of symbol video_devdata
[    7.533594] v4l2_mem2mem: Unknown symbol video_devdata (err -22)
[    7.535319] v4l2_mem2mem: disagrees about version of symbol v4l2_event_pending
[    7.542532] v4l2_mem2mem: Unknown symbol v4l2_event_pending (err -22)
===============================

So v4l2_fh struct is modified to does not have dependency
for CONFIG_V4L2_MEM2MEM_DEV.
Signed-off-by: Seungchul Kim <sc377.kim@samsung.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/v4l2-core/v4l2-ioctl.c

@@ -2805,13 +2805,11 @@ static struct mutex *v4l2_ioctl_get_lock(struct video_device *vdev,
 {
 	if (_IOC_NR(cmd) >= V4L2_IOCTLS)
 		return vdev->lock;
-#if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV)
 	if (vfh && vfh->m2m_ctx &&
 	    (v4l2_ioctls[_IOC_NR(cmd)].flags & INFO_FL_QUEUE)) {
 		if (vfh->m2m_ctx->q_lock)
 			return vfh->m2m_ctx->q_lock;
 	}
-#endif
 	if (vdev->queue && vdev->queue->lock &&
 			(v4l2_ioctls[_IOC_NR(cmd)].flags & INFO_FL_QUEUE))
 		return vdev->queue->lock;

include/media/v4l2-fh.h

@@ -53,9 +53,7 @@ struct v4l2_fh {
 	unsigned int		navailable;
 	u32			sequence;
 
-#if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV)
 	struct v4l2_m2m_ctx	*m2m_ctx;
-#endif
 };
 
 /**