debuginfod: store only canonicalized sref pathnames in database

debuginfod: store only canonicalized sref pathnames in database

Since PR25548, we let debuginfod answer /buildid/HEX/source/PATH
queries with both canonicalized and raw PATHs.  It canonicalizes
incoming paths, but still stored the raw paths in the database too.
This near-dupe storage is not needed, since the queries would always
find the canonicalized version too, so stop doing that.  This saves
database space/time.

Signed-off-by: Frank Ch. Eigler <fche@redhat.com>