IB/mlx5: Don't clean uninitialized UMR resources

In case we failed to create UMR resources, mark them as invalid so we
won't try to destroy them on the unwind path.

Add the relevant checks to destroy_umrc_res(), this is done for the
unlikely event ib_register_device() or create_umr_res() err out and we
try to destroy invalid objects.

Fixes: 42cea83f ("IB/mlx5: Fix cleanup order on unload")
Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>