IB/mlx5: Return appropriate error code instead of ENOMEM

When mlx5_ib_stage_init_init() fails, return the error code related to
failure instead of -ENOMEM.

Fixes: 16c1975f ("IB/mlx5: Create profile infrastructure to add and remove stages")
Link: https://lore.kernel.org/r/20210127150010.1876121-8-leon@kernel.org


Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>