Python3 doesn't seem to allow you to tell whether an object is a class

PyClass_Check and everything it relied on seems gone from Python3.7.  So
I won't check whether it is a class first...

Also cleaned up a couple of warnings.

llvm-svn: 373679

lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp

@@ -892,8 +892,6 @@ PythonCallable::ArgInfo PythonCallable::GetNumInitArguments() const {
   if (!IsValid())
     return result;
   PyObject *py_func_obj = m_py_obj;
-  if (!PyClass_Check(m_py_obj))
-    return result;
 
   PythonObject __init__ = GetAttributeValue("__init__");
   if (__init__.IsValid() ) {