net/sched: taprio: Drop unnecessary NULL check after container_of

The rcu_head pointer passed to taprio_free_sched_cb is never NULL.
That means that the result of container_of() operations on it is also
never NULL, even though rcu_head is the first element of the structure
embedding it. On top of that, it is misleading to perform a NULL check
on the result of container_of() because the position of the contained
element could change, which would make the check invalid. Remove the
unnecessary NULL check.

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: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/sch_taprio.c

@@ -114,9 +114,6 @@ static void taprio_free_sched_cb(struct rcu_head *head)
 	struct sched_gate_list *sched = container_of(head, struct sched_gate_list, rcu);
 	struct sched_entry *entry, *n;
 
-	if (!sched)
-		return;
-
 	list_for_each_entry_safe(entry, n, &sched->entries, list) {
 		list_del(&entry->list);
 		kfree(entry);