ibmvnic: set ltb->buff to NULL after freeing

free_long_term_buff() checks ltb->buff to decide whether we have a long
term buffer to free. So set ltb->buff to NULL afer freeing. While here,
also clear ->map_id, fix up some coding style and log an error.

Fixes: 9c4eaabd ("Check CRQ command return codes")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmvnic.c

@@ -211,12 +211,11 @@ static int alloc_long_term_buff(struct ibmvnic_adapter *adapter,
 	mutex_lock(&adapter->fw_lock);
 	adapter->fw_done_rc = 0;
 	reinit_completion(&adapter->fw_done);
-	rc = send_request_map(adapter, ltb->addr,
-			      ltb->size, ltb->map_id);
+
+	rc = send_request_map(adapter, ltb->addr, ltb->size, ltb->map_id);
 	if (rc) {
-		dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
-		mutex_unlock(&adapter->fw_lock);
-		return rc;
+		dev_err(dev, "send_request_map failed, rc = %d\n", rc);
+		goto out;
 	}
 
 	rc = ibmvnic_wait_for_completion(adapter, &adapter->fw_done, 10000);
@@ -224,20 +223,23 @@ static int alloc_long_term_buff(struct ibmvnic_adapter *adapter,
 		dev_err(dev,
 			"Long term map request aborted or timed out,rc = %d\n",
 			rc);
-		dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
-		mutex_unlock(&adapter->fw_lock);
-		return rc;
+		goto out;
 	}
 
 	if (adapter->fw_done_rc) {
 		dev_err(dev, "Couldn't map long term buffer,rc = %d\n",
 			adapter->fw_done_rc);
+		rc = -1;
+		goto out;
+	}
+	rc = 0;
+out:
+	if (rc) {
 		dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
-		mutex_unlock(&adapter->fw_lock);
-		return -1;
+		ltb->buff = NULL;
 	}
 	mutex_unlock(&adapter->fw_lock);
-	return 0;
+	return rc;
 }
 
 static void free_long_term_buff(struct ibmvnic_adapter *adapter,
@@ -257,6 +259,8 @@ static void free_long_term_buff(struct ibmvnic_adapter *adapter,
 	    adapter->reset_reason != VNIC_RESET_TIMEOUT)
 		send_request_unmap(adapter, ltb->map_id);
 	dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
+	ltb->buff = NULL;
+	ltb->map_id = 0;
 }
 
 static int reset_long_term_buff(struct ibmvnic_adapter *adapter,