pre-upload: fix a few style/compatibility issues

A few review notes came after CL:1336039 landed.

 * os.path.join: might as well use this everywhere we're constructing
   paths out of _get_hooks_dir()
 * it's a little clearer to name the non-msg HookFailure() args

TEST=unit tests; run a few good/bad commits through .../

Change-Id: I401fe6c8bf02a3020122fa0875b2beb23345be27
Commit-Ready: Brian Norris <>
Tested-by: Brian Norris <>
Reviewed-by: Mike Frysinger <>
1 file changed