Merge tag '6.3-rc6-smb311-client-negcontext-fix' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fix from Steve French:
 "Small client fix for better checking for smb311 negotiate context
  overflows, also marked for stable"

* tag '6.3-rc6-smb311-client-negcontext-fix' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix negotiate context parsing