net/mlx5e: Fix inner tirs handling

In the cited commit inner_tirs argument was added to create and destroy
inner tirs, and no indication was added to mlx5e_modify_tirs_hash()
function. In order to have a consistent handling, use
inner_indir_tir[0].tirn in tirs destroy/modify function as an indication
to whether inner tirs are created.
Inner tirs are not created for representors and before this commit,
a call to mlx5e_modify_tirs_hash() was sending HW commands to
modify non-existent inner tirs.

Fixes: 46dc933c ("net/mlx5e: Provide explicit directive if to create inner indirect tirs")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>