parallels_driver: Utilize parallelsDomObjFromDomain()
parallels_driver: Utilize parallelsDomObjFromDomain()

Instead of each API copying the same lines of code, lets use the
generic function designed just for that purpose. At the same time,
drop useless connection object locking in some functions.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

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