IB/core: Fix missing RDMA cgroups release in case of failure to register device

commit 2fb4f4ea upstream.

During IB device registration process, if query_device() fails or if
ib_core fails to registers sysfs entries, rdma cgroup cleanup is
skipped.

Cc: <stable@vger.kernel.org> # v4.2+
Fixes: 4be3a4fa ("IB/core: Fix kernel crash during fail to initialize device")
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>