IB/cm: Release previously acquired reference counter in the cm_id_priv

In failure flow, the reference counter acquired was not released,
and the following error was reported:

  drivers/infiniband/core/cm.c:3373 cm_lap_handler() warn: inconsistent
			refcounting 'cm_id_priv->refcount.refs.counter':

Fixes: 7345201 ("IB/cm: Improve the calling of cm_init_av_for_lap and cm_init_av_by_path")
Link: https://lore.kernel.org/r/7615f23bbb5c5b66d03f6fa13e1c99d51dae6916.1642581448.git.leonro@nvidia.com
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: MarkZhang81

drivers/infiniband/core/cm.c

@@ -3322,7 +3322,7 @@ static int cm_lap_handler(struct cm_work *work)
 	ret = cm_init_av_by_path(param->alternate_path, NULL, &alt_av);
 	if (ret) {
 		rdma_destroy_ah_attr(&ah_attr);
-		return -EINVAL;
+		goto deref;
 	}
 
 	spin_lock_irq(&cm_id_priv->lock);