Fixing a potential control may reach end of non-void function issue

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@162685 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/scripts/Python/python-wrapper.swig b/scripts/Python/python-wrapper.swig
index ea8fb29..113447e 100644
--- a/scripts/Python/python-wrapper.swig
+++ b/scripts/Python/python-wrapper.swig
@@ -981,6 +981,7 @@
         SWIG_PYTHON_THREAD_END_BLOCK;
         return result;
     }
+    return 0;
 }
 
 // For the LogOutputCallback functions