Fix strftime string in fingerprint script

There was an extra % in the strftime string used in the fingerprint
script to name the output files. It worked fine in python 2.6 on mac
os, but was producing bad file names in python 2.7 on linux.

utils/fingerprint/fingerprint.py

@@ -159,7 +159,7 @@ def validate(opts, args, parser):
   if opts.dir:
     fname = opts.output
     if fname is None:
-      fname = datetime.today().strftime("%Y-%m%-%d_%H-%M-%S") + ".fp"
+      fname = datetime.today().strftime("%Y-%m-%d_%H-%M-%S") + ".fp"
     path = os.path.join(opts.dir, fname)
     opts.output_file = path
     opts.output = file(path, "w")