prebuilt.py: fix variant detection regex

prebuilt.py

 #!/usr/bin/python
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import datetime
 import multiprocessing
 import optparse
 import os
 import re
@@ skipping 349 matching lines @@
 
     Returns
       A string path to a make.conf file to be updated.
   """
   if _HOST_TARGET == target:
     # We are host.
     # Without more examples of hosts this is a kludge for now.
     # TODO(Scottz): as new host targets come online expand this to
     # work more like boards.
     make_path =  _PREBUILT_MAKE_CONF[target]
-  elif re.match('.*?-.*?_.*', target):
+  elif re.match('.*?_.*', target):
     # We are a board variant
     overlay_str = 'overlay-variant-%s' % target.replace('_', '-')
     make_path = os.path.join(_BINHOST_BASE_DIR, overlay_str, 'make.conf')
   elif re.match('.*?-\w+', target):
     overlay_str = 'overlay-%s' % target
     make_path = os.path.join(_BINHOST_BASE_DIR, overlay_str, 'make.conf')
   else:
     raise UnknownBoardFormat('Unknown format: %s' % target)
 
   return os.path.join(make_path)
@@ skipping 105 matching lines @@
                    options.binhost_base_url, git_sync=options.git_sync)
 
   if options.board:
     UploadPrebuilt(options.build_path, options.upload, version,
                    options.binhost_base_url, board=options.board,
                    git_sync=options.git_sync)
 
 
 if __name__ == '__main__':
   main()