iwlwifi: mvm: write queue_sync_state only for sync

iwlwifi: mvm: write queue_sync_state only for sync

We use mvm->queue_sync_state to wait for synchronous queue sync
messages, but if an async one happens inbetween we shouldn't
clear mvm->queue_sync_state after sending the async one, that
can run concurrently (at least from the CPU POV) with another
synchronous queue sync.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210331121101.d11c9bcdb4aa.I0772171dbaec87433a11513e9586d98b5d920b5f@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>