core: Further unify API to create files

We now have just one place which writes to the filesystem.  Wrap a
temporary file allocation API on top of that.

src/libotutil/ot-gio-utils.h

@@ -51,24 +51,6 @@ gboolean ot_gio_splice_and_checksum (GOutputStream  *out,
                                      GCancellable   *cancellable,
                                      GError        **error);
 
-
-gboolean ot_gfile_create_tmp (GFile       *dir,
-                              const char  *prefix,
-                              const char  *suffix,
-                              int          mode,
-                              GFile      **out_file,
-                              GOutputStream **out_stream,
-                              GCancellable *cancellable,
-                              GError       **error);
-
-gboolean ot_gfile_create_tmp_symlink (const char  *target,
-                                      GFile       *dir,
-                                      const char  *prefix,
-                                      const char  *suffix,
-                                      GFile      **out_file,
-                                      GCancellable *cancellable,
-                                      GError       **error);
-
 gboolean ot_gfile_merge_dirs (GFile    *destination,
                               GFile    *src,
                               GCancellable *cancellable,