Add extack message to return exact message to user when adding invalid
filter with conflict flags for TC action.

In previous implement we just return EINVAL which is confusing for user.
Signed-off-by: NBaowen Zheng <baowen.zheng@corigine.com>
Reviewed-by: NRoi Dayan <roid@nvidia.com>
Link: https://lore.kernel.org/r/1646191769-17761-1-git-send-email-baowen.zheng@corigine.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>