node_device: Unlock obj in case of an error too
Unlock @obj in case of an error too.
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>