only show all files found in debug

a single -v flag shouldn't flood the console with all the files in the
path specified, it makes -v basically useless

this way, -v can also be used with --progress to have nicer output:

initializing cache
reading files cache
processing files
  5.20 GB O   2.66 GB C  25.13 MB D 27576 N baz/...

borg/archiver.py

@@ -57,7 +57,7 @@ class Archiver:
         logger.info(msg)
 
     def print_status(self, status, path):
-        logger.info("%1s %s", status, remove_surrogates(path))
+        logger.debug("%1s %s", status, remove_surrogates(path))
 
     def do_serve(self, args):
         """Start in server mode. This command is usually not used manually.