net/mlx5: DR, Init lists that are used in rule's member

[ Upstream commit df55c558 ]

Whenever adding new member of rule object we attach it to 2 lists,
These 2 lists should be initialized first.

Fixes: 41d07074 ("net/mlx5: DR, Expose steering rule functionality")
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>