iwlwifi: mvm: take the required lock when clearing time event data

When receiving a session protection end notification, the time event
data is cleared without holding the required lock. Fix it.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200306151128.a49846a634e4.Id1ada7c5a964f5e25f4d0eacc2c4b050015b46a2@changeid

drivers/net/wireless/intel/iwlwifi/mvm/time-event.c

@@ -785,7 +785,9 @@ void iwl_mvm_rx_session_protect_notif(struct iwl_mvm *mvm,
 		if (!le32_to_cpu(notif->status)) {
 			iwl_mvm_te_check_disconnect(mvm, vif,
 						    "Session protection failure");
+			spin_lock_bh(&mvm->time_event_lock);
 			iwl_mvm_te_clear_data(mvm, te_data);
+			spin_unlock_bh(&mvm->time_event_lock);
 		}
 
 		if (le32_to_cpu(notif->start)) {
@@ -801,7 +803,9 @@ void iwl_mvm_rx_session_protect_notif(struct iwl_mvm *mvm,
 			 */
 			iwl_mvm_te_check_disconnect(mvm, vif,
 						    "No beacon heard and the session protection is over already...");
+			spin_lock_bh(&mvm->time_event_lock);
 			iwl_mvm_te_clear_data(mvm, te_data);
+			spin_unlock_bh(&mvm->time_event_lock);
 		}
 
 		goto out_unlock;