net: wireless: ath9k: avoid possible NULL pointer dereference
Code in ath9k_hw_set_clockrate function indicates that ah->curchan
(and thus chan local variable) may be NULL. If that is indeed the
case, IS_CHAN_HT40(chan) check has to be performed only in branch
where chan is not NULL. Moving the code under already existing
if condition fixes this issue.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>