virbuftest: remove unnecessary labels
virbuftest: remove unnecessary labels

Remove the ret variables and labels from functions that no longer need
them.

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Reviewed-by: Erik Skultety <2c14d38fa47c8799f1b9c16280abe27f8edfec6e@redhat.com>

olafhering/libvirt,jardasgit/libvirt,zippy2/libvirt,jardasgit/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,crobinso/libvirt,olafhering/libvirt,crobinso/libvirt,nertpinx/libvirt,libvirt/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,zippy2/libvirt,libvirt/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,libvirt/libvirt,jardasgit/libvirt,jfehlig/libvirt,jfehlig/libvirt,zippy2/libvirt,jardasgit/libvirt,crobinso/libvirt,libvirt/libvirt,olafhering/libvirt,zippy2/libvirt,crobinso/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,olafhering/libvirt