Using Fusil the fuzzer, I found a "minor" bug in _hotshot module: it 
doesn't check correctly the errors in hotshot_logreader(). On error, 
an exception is raised (eg. by eof_error()) but the result is a 
pointer to a new allocated object instead of NULL.

Here is a patch to delete the new created object (using Py_DECREF) and 
return NULL. It uses an ugly goto, but goto is sometimes useful to 
avoid code duplication on error handling (eg. see Linux source code).

Example to reproduce the bug:
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import _hotshot, gc
_hotshot.logreader(".")
gc.collect()
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