selftests: drv-net: rss_ctx: Don't assume indirection table is present

The test_rss_context_dump() test assumes the indirection table is always
supported, which is not true for all drivers, e.g., virtio_net when
VIRTIO_NET_F_RSS is disabled.

Skip the check if 'indir' is not present.

Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250318112426.386651-1-gal@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>