Bug fix for an issue which has been around for about a decade.
We got away with it because the enumeration was larger than needed.

Fixes: 7ba699c6 ("[NET_SCHED]: Convert actions from rtnetlink to new netlink API")
Suggested-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NJamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>