libostree: added empty ot_cleanup_{read,write}_archive macros.

Added empty macros for ot_cleanup_{read,write}_archive to fix
errors when compiling without libarchive.

Signed-off-by: Krisztian Litkey <krisztian.litkey@intel.com>

Closes: #677
Approved by: cgwalters

src/libostree/ostree-libarchive-private.h

@@ -37,6 +37,9 @@ GLNX_DEFINE_CLEANUP_FUNCTION (void *, flatpak_local_free_write_archive, archive_
 
 GLNX_DEFINE_CLEANUP_FUNCTION (void *, flatpak_local_free_read_archive, archive_read_free)
 #define ot_cleanup_read_archive __attribute__((cleanup (flatpak_local_free_read_archive)))
+#else
+#define ot_cleanup_write_archive
+#define ot_cleanup_read_archive
 #endif
 
 G_END_DECLS