Fix showbootdata handling when invoked with options but no arguments

bootperf-bin/showbootdata

 #!/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.
 
 """A command to display summary statistics from runs of 'bootperf'.
 
 Command line options allow selecting from one of two sets of
 performance statistics:  The boot time statistics (selected by
@@ skipping 89 matching lines @@
   elif options.use_diskstats:
     use_timestats = False
   else:
     use_timestats = True
   if options.eventnames:
     keylist = []
     for kl in options.eventnames:
       keylist.extend(kl.split(','))
   else:
     keylist = None
+  if not args:
+    args = ["."]
   printfunc(args, use_timestats, keylist)
 
 if __name__ == "__main__":
-  if len(sys.argv) > 1:
-    main(sys.argv[1:])
-  else:
-    main(["."])
+  main(sys.argv[1:])