virsh: avoid unnecessary progress updates
virsh: avoid unnecessary progress updates

There is no need to call virshPrintJobProgress() unless the block job's
cur or end cursors have changed since the last iteration.

Signed-off-by: Michael Chapman <a17fed27eaa842282862ff7c1b9c8395a26ac320@very.puzzling.org>

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