media: media/test_drivers: Drop unnecessary NULL check after container_of

The result of container_of() operations is never NULL unless the embedded
element is the first element of the structure. This is not the case here.
The NULL check is therefore unnecessary and misleading. Remove it.

This change was made automatically with the following Coccinelle script.

@@
type t;
identifier v;
statement s;
@@

<+...
(
  t v = container_of(...);
|
  v = container_of(...);
)
  ...
  when != v
- if (\( !v \| v == NULL \) ) s
...+>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/test-drivers/vim2m.c

@@ -624,11 +624,6 @@ static void device_work(struct work_struct *w)
 
 	curr_ctx = container_of(w, struct vim2m_ctx, work_run.work);
 
-	if (!curr_ctx) {
-		pr_err("Instance released before the end of transaction\n");
-		return;
-	}
-
 	vim2m_dev = curr_ctx->dev;
 
 	src_vb = v4l2_m2m_src_buf_remove(curr_ctx->fh.m2m_ctx);