qemuPrepareNVRAM: Save domain conf only if domain's persistent
qemuPrepareNVRAM: Save domain conf only if domain's persistent

In one of my previous patches (3a3c3780b) I've tried to fix the
problem of nvram path disappearing on a domain that's been
started and shut down again. I fixed this by explicitly saving
domain's config file.  However, I did a bit of clumsy without
realizing we have a transient domains for which we don't save the
config file. Hence, any domain using UEFI became persistent.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

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