net/mlx5: Fix wrong comment

A control irq may be allocated from the parent device's pool in case
there is no SF dedicated pool. This could happen when there are not
enough vectors available for SFs.
Signed-off-by: NEli Cohen <elic@nvidia.com>
Reviewed-by: NShay Drory <shayd@nvidia.com>
Signed-off-by: NSaeed Mahameed <saeedm@nvidia.com>
Reviewed-by: NJacob Keller <jacob.e.keller@intel.com>

drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c

@@ -394,7 +394,9 @@ struct mlx5_irq *mlx5_ctrl_irq_request(struct mlx5_core_dev *dev)
 		return ERR_PTR(-ENOMEM);
 	cpumask_copy(req_mask, cpu_online_mask);
 	if (!mlx5_irq_pool_is_sf_pool(pool)) {
-		/* In case we are allocating a control IRQ for PF/VF */
+		/* In case we are allocating a control IRQ from a pci device's pool.
+		 * This can happen also for a SF if the SFs pool is empty.
+		 */
 		if (!pool->xa_num_irqs.max) {
 			cpumask_clear(req_mask);
 			/* In case we only have a single IRQ for PF/VF */