net: sched: sch_taprio: fix memleak in error path for sched list parse

In error case, all entries should be freed from the sched list
before deleting it. For simplicity use rcu way.

Fixes: 5a781ccb ("tc: Add support for configuring the taprio scheduler")
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>