qemu: process: Refactor setup of memory ballooning
qemu: process: Refactor setup of memory ballooning

Since the monitor code now supports ullongs when setting balloon size,
drop the legacy code with overflow checking.

Additionally the comment mentioning that the job is treated as a sync
job does not make sense any more since the monitor is entered
asynchronously.

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