Fix option parsing.

src/python/m5/main.py:
    Don't allow interspersed arguments, it messes things up

--HG--
extra : convert_revision : 8f1bcf4391f570741d92bf5420879862a48f6016

src/python/m5/main.py

@@ -50,6 +50,7 @@ All Rights Reserved
 parser = optparse.OptionParser(usage=usage, version=version,
                                description=brief_copyright,
                                formatter=optparse.TitledHelpFormatter())
+parser.disable_interspersed_args()
 
 # current option group
 group = None