net/mlx5: Fix error print in case of IRQ request failed

[ Upstream commit aa968f9 ]

In case IRQ layer failed to find or to request irq, the driver is
printing the first cpu of the provided affinity as part of the error
print. Empty affinity is a valid input for the IRQ layer, and it is
an error to call cpumask_first() on empty affinity.

Remove the first cpu print from the error message.

Fixes: c36326d ("net/mlx5: Round-Robin EQs over IRQs")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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

@@ -346,8 +346,8 @@ static struct mlx5_irq *irq_pool_request_affinity(struct mlx5_irq_pool *pool,
 	new_irq = irq_pool_create_irq(pool, affinity);
 	if (IS_ERR(new_irq)) {
 		if (!least_loaded_irq) {
-			mlx5_core_err(pool->dev, "Didn't find IRQ for cpu = %u\n",
-				      cpumask_first(affinity));
+			mlx5_core_err(pool->dev, "Didn't find a matching IRQ. err = %ld\n",
+				      PTR_ERR(new_irq));
 			mutex_unlock(&pool->lock);
 			return new_irq;
 		}