ieee802154: fix one possible memleak in adf7242_probe

ieee802154: fix one possible memleak in adf7242_probe

[ Upstream commit 66673f96f0f968b991dc38be06102246919c663c ]

When probe fail, we should destroy the workqueue.

Fixes: 2795e8c25161 ("net: ieee802154: fix a potential NULL pointer dereference")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Link: https://lore.kernel.org/r/20200717090121.2143-1-liujian56@huawei.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>