ath9k: fix dynamic WEP related regression

commit 7a532fe7
ath9k_hw: fix interpretation of the rx KeyMiss flag

This commit used the rx key miss indication to detect packets that were
passed from the hardware without being decrypted, however it seems that
this bit is not only undefined in the static WEP case, but also for
dynamically allocated WEP keys. This caused a regression when using
WEP-LEAP.

This patch fixes the regression by keeping track of which key indexes
refer to CCMP keys and only using the key miss indication for those.

Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>