mlx4: Fix missing error code in mlx4_load_one()

mlx4: Fix missing error code in mlx4_load_one()

The error code is missing in this code scenario, add the error code
'-EINVAL' to the return value 'err'.

Eliminate the follow smatch warning:

drivers/net/ethernet/mellanox/mlx4/main.c:3538 mlx4_load_one() warn:
missing error code 'err'.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Fixes: 7ae0e400cd93 ("net/mlx4_core: Flexible (asymmetric) allocation of EQs and MSI-X vectors for PF/VFs")
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>