net/mlx5: Fix check for allocation failure in comp_irqs_request_pci()

This function accidentally dereferences "cpus" instead of returning
directly.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202305200354.KV3jU94w-lkp@intel.com/
Fixes: b48a0f72

 ("net/mlx5: Refactor completion irq request/release code")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>