iwlwifi: mvm: replace BUG_ON by WARN_ON in scan.c

While the scan_cmd should really be allocated in init (and
we do fail init in case the allocation failed), it doesn't
mean we should lock up the machine if something really bad
happened.
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/mvm/scan.c

@@ -348,7 +348,10 @@ int iwl_mvm_scan_request(struct iwl_mvm *mvm,
 	struct iwl_mvm_scan_params params = {};
 
 	lockdep_assert_held(&mvm->mutex);
-	BUG_ON(mvm->scan_cmd == NULL);
+
+	/* we should have failed registration if scan_cmd was NULL */
+	if (WARN_ON(mvm->scan_cmd == NULL))
+		return -ENOMEM;
 
 	IWL_DEBUG_SCAN(mvm, "Handling mac80211 scan request\n");
 	mvm->scan_status = IWL_MVM_SCAN_OS;

drivers/net/wireless/iwlwifi/pcie/trans.c

@@ -1278,6 +1278,8 @@ static int iwl_trans_pcie_wait_txq_empty(struct iwl_trans *trans, u32 txq_bm)
 			continue;
 		if (!(BIT(cnt) & txq_bm))
 			continue;
+
+		IWL_DEBUG_TX_QUEUES(trans, "Emptying queue %d...\n", cnt);
 		txq = &trans_pcie->txq[cnt];
 		q = &txq->q;
 		wr_ptr = ACCESS_ONCE(q->write_ptr);
@@ -1300,6 +1302,7 @@ static int iwl_trans_pcie_wait_txq_empty(struct iwl_trans *trans, u32 txq_bm)
 			ret = -ETIMEDOUT;
 			break;
 		}
+		IWL_DEBUG_TX_QUEUES(trans, "Queue %d is now empty.\n", cnt);
 	}
 
 	if (!ret)