ibmvnic: Potential NULL dereference in clean_one_tx_pool()

There is an && vs || typo here, which potentially leads to a NULL
dereference.

Fixes: e9e1e978 ("ibmvnic: Update TX pool cleaning routine")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmvnic.c

@@ -1135,7 +1135,7 @@ static void clean_one_tx_pool(struct ibmvnic_adapter *adapter,
 	u64 tx_entries;
 	int i;
 
-	if (!tx_pool && !tx_pool->tx_buff)
+	if (!tx_pool || !tx_pool->tx_buff)
 		return;
 
 	tx_entries = tx_pool->num_buffers;