net/mlx5e: Properly initialize flow attributes for slow path eswitch rule deletion

When a neighbour is resolved, we delete the goto slow path rule from HW.

The eswitch flow attributes where not properly initialized on that case,
hence we mess up the eswitch refcounts for chain zero (the default one).

Fix that along with making sure to use semicolons and not commas on that code;

Fixes: 5dbe906f ('net/mlx5e: Use a slow path rule instead if vxlan neighbour isn't available')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>