From: Vladimir Oltean <olteanv@gmail.com>
Date: Wed, 28 Aug 2019 17:48:27 +0300

taprio_init may fail earlier than this line:

	list_add(&q->taprio_list, &taprio_list);

i.e. due to the net device not being multi queue.

Attempting to remove q from the global taprio_list when it is not part
of it will result in a kernel panic.

Fix it by iterating through the list and removing it only if found.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>

I don't like this solution for two reaons, I think it's actually
error prone, and now every taprio_destroy() eats the cost of traversing
the entire list.

The whole reason to use a list head is O(1) removal.

Just init the list head early in the creation then the list_del() just
works.