[doc/recipes.py] fix issue when running recipes.py from .

doc/recipes.py

 #!/usr/bin/env python
 
 # Copyright 2017 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Bootstrap script to clone and forward to the recipe engine tool.
 
 *******************
 ** DO NOT MODIFY **
@@ skipping 169 matching lines @@
 
   return engine_path
 
 
 def main():
   if '--verbose' in sys.argv:
     logging.getLogger().setLevel(logging.INFO)
 
   repo_root = os.path.abspath(
     _git_output(['rev-parse', '--show-toplevel'],
-                cwd=os.path.dirname(__file__)).strip())
+                cwd=os.path.abspath(os.path.dirname(__file__))).strip())
 
   # TODO(iannucci): Actually make the location of recipes.cfg configurable.
   recipes_cfg_path = os.path.join(repo_root, 'infra', 'config', 'recipes.cfg')
 
   engine_path = checkout_engine(repo_root, recipes_cfg_path)
 
   args = ['--package', recipes_cfg_path] + sys.argv[1:]
   return _subprocess_call([
       sys.executable, '-u',
       os.path.join(engine_path, 'recipes.py')] + args)
 
 
 if __name__ == '__main__':
   sys.exit(main())