net: move stale comment about ntuple validation

net: move stale comment about ntuple validation

Gal points out that the comment now belongs further down, since
the original if condition was split into two in
commit de7f7582dff2 ("net: ethtool: prevent flow steering to RSS contexts which don't exist")

Link: https://lore.kernel.org/de4a2a8a-1eb9-4fa8-af87-7526e58218e9@nvidia.com
Reviewed-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20250214224340.2268691-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>