qemu: Return in from qemuDomainRemove*Device
qemu: Return in from qemuDomainRemove*Device

Some of the APIs already return int since they can produce errors that
need to be propagated. For consistency reasons, this patch changes the
rest of the APIs to also return int even though they do not fail or
report any errors.

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