kernel: nbd: defer config unlock in nbd_genl_connect

In the Linux kernel, the following vulnerability has been resolved: nbd: defer config unlock in nbdgenlconnect There is one use-after-free warning when running NBDCMDCONNECT and NBDCLEARSOCK: nbdgenlconnect nbdallocandinitconfig // configrefs=1 nbdstartdevice // configrefs=2 set NBDRTHASCONFIGREF...