qemu_domain_namespace: Drop unused @cfg argument
qemu_domain_namespace: Drop unused @cfg argument

There is a lot of functions called from
qemuDomainBuildNamespace() that accept @cfg
(virQEMUDriverConfigPtr) as an argument and don't use it.
Historically, it was done so that all qemuDomainSetupAll*()
functions look the same.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

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