core: Return input stream for raw repositories too
core: Return input stream for raw repositories too

This bug is more obvious when fsck is rebased on top of
ostree_repo_load_file().

GNOME/ostree,sujitfulse/ostree,resin-io/ostree,sujitfulse/ostree,leandrosansilva/ostree,sujitfulse/ostree,GNOME/ostree,gatispaeglis/ostree,sujitfulse/ostree,gatispaeglis/ostree,resin-io/ostree,GNOME/ostree,gatispaeglis/ostree,resin-io/ostree,GNOME/ostree,leandrosansilva/ostree,leandrosansilva/ostree,GNOME/ostree,resin-io/ostree,resin-io/ostree,leandrosansilva/ostree,sujitfulse/ostree,gatispaeglis/ostree,gatispaeglis/ostree,leandrosansilva/ostree,gatispaeglis/ostree