bhyve: fix virObjectUnlock() usage
bhyve: fix virObjectUnlock() usage

In a number of places in the bhyve driver, virObjectUnlock()
is called with an arg without check if the arg is non-NULL, which
could result in passing NULL value and a warning like:

virObjectUnlock:340 : Object 0x0 ((unknown)) is not a virObjectLockable instance

* src/bhyve/bhyve_driver.c (bhyveDomainGetInfo)
(bhyveDomainGetState, bhyveDomainGetAutostart)
(bhyveDomainSetAutostart, bhyveDomainIsActive)
(bhyveDomainIsPersistent, bhyveDomainGetXMLDesc)
(bhyveDomainUndefine, bhyveDomainLookupByUUID)
(bhyveDomainLookupByName, bhyveDomainLookupByID)
(bhyveDomainCreateWithFlags, bhyveDomainOpenConsole):
Check if arg is not NULL before calling virObjectUnlock on it.

libvirt/libvirt,zippy2/libvirt,taget/libvirt,taget/libvirt,elmarco/libvirt,eskultety/libvirt,taget/libvirt,olafhering/libvirt,jardasgit/libvirt,datto/libvirt,datto/libvirt,eskultety/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,elmarco/libvirt,agx/libvirt,rlaager/libvirt,olafhering/libvirt,zippy2/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,eskultety/libvirt,taget/libvirt,VenkatDatta/libvirt,datto/libvirt,fabianfreyer/libvirt,shugaoye/libvirt,olafhering/libvirt,nertpinx/libvirt,jardasgit/libvirt,andreabolognani/libvirt,nertpinx/libvirt,andreabolognani/libvirt,agx/libvirt,rlaager/libvirt,nertpinx/libvirt,jfehlig/libvirt,crobinso/libvirt,andreabolognani/libvirt,olafhering/libvirt,fabianfreyer/libvirt,libvirt/libvirt,crobinso/libvirt,rlaager/libvirt,rlaager/libvirt,datto/libvirt,nertpinx/libvirt,eskultety/libvirt,elmarco/libvirt,crobinso/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,rlaager/libvirt,elmarco/libvirt,elmarco/libvirt,zippy2/libvirt,andreabolognani/libvirt,jfehlig/libvirt,agx/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,taget/libvirt,eskultety/libvirt,jardasgit/libvirt,shugaoye/libvirt,jfehlig/libvirt,datto/libvirt,jfehlig/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,agx/libvirt,shugaoye/libvirt,crobinso/libvirt,libvirt/libvirt,agx/libvirt,zippy2/libvirt,nertpinx/libvirt,libvirt/libvirt