iwlwifi: pcie: fix TX queue locking

When updating the write pointer, the TX queue should be locked
to get consistent state, fix that in the interrupt handler.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

diff --cc drivers/net/wireless/iwlwifi/pcie/rx.c
Simple merge