ethtool: ntuple: fix rss + ring_cookie check

The info.flow_type is for RXFH commands, ntuple flow_type is inside
the flow spec. The check currently does nothing, as info.flow_type
is 0 (or even uninitialized by user space) for ETHTOOL_SRXCLSRLINS.

Fixes: 9e43ad7a ("net: ethtool: only allow set_rxnfc with rss + ring_cookie if driver opts in")
Reviewed-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20250201013040.725123-3-kuba@kernel.org


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