ath9k_htc: Remove useless cancel_work_sync

There is no need to cancel the PS work when disassociation
happens. The work handlers are cancelled in the stop()
callback.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
1 file changed