wlan_pdev_chan_match used to take current vdev lock on current
iterating vdev and then on vdev for which channel set is triggered.
If two cores happed to try setting channel on two different vdevs,
cross locking may occur. Fix this by releasing one lock and then
acquiring other lock.
Change-Id: Ic1a6ca448c6d535e949102bc5a8a45971c8babd2
CRs-Fixed: 2460054