cfg.mk: Only force _LAST enum on VIR_ENUM_IMPL second line
cfg.mk: Only force _LAST enum on VIR_ENUM_IMPL second line

Drop the checking for _LAST optionally on the first line, previous
patch removed all those instances

Signed-off-by: Cole Robinson <7cd45ff6ad1fb7cf556a02797d774247851499f8@redhat.com>

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