net/mlx5: Bridge, release bridge in same function where it is taken

net/mlx5: Bridge, release bridge in same function where it is taken

Refactor mlx5_esw_bridge_vport_link() to release the bridge instance if
mlx5_esw_bridge_vport_init() returned an error instead of relying on it to
release the bridge. This improves the design because object instance is
taken and released in same layer and simplifies following patches that add
more logic to mlx5_esw_bridge_vport_link().

Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>