conf: use a leading space in virDomainVirtioNetDriverFormat
conf: use a leading space in virDomainVirtioNetDriverFormat

Instead of formatting a space after every option.

Reviewed-by: Pavel Hrdina <d4772d05997b8abf035041e3b4f4996380ea7e7a@redhat.com>

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