mlxsw: core_acl_flex_actions: Rename Trap / Discard Action to Trap Action

The Trap / Discard Action action got renamed in PRM, so rename it in the
code as well.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>