The commit "ath9k: configure beacons based on hw opmode" introduced
a regression which leads to kernel panic. Failed to stop ani timer
during the driver unload while any of the beaconing vif is running.
Signed-off-by: NRajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>