RDMA/core: Change rdma_get_gid_attr returned error code

Change the error code returned from rdma_get_gid_attr when the GID entry
is invalid but the GID index is in the gid table size range to -ENODATA
instead of -EINVAL.

This change is done in order to provide a more accurate error reporting to
be used by the new GID query API in user space. Nevertheless, -EINVAL is
still returned from sysfs in the aforementioned case to maintain
compatibility with user space that expects -EINVAL.

Link: https://lore.kernel.org/r/20200923165015.2491894-2-leon@kernel.org


Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>