Fix warning when __Pyx_Print is not used

Cython/Compiler/Nodes.py

@@ -4914,6 +4914,9 @@ static int __Pyx_PrintOne(PyObject *o) {
     if (PyFile_WriteString("\n", f) < 0)
         return -1;
     return 0;
+    /* the line below is just to avoid compiler
+     * compiler warnings about unused functions */
+    __Pyx_Print(NULL, 0);
 }
 
 #else /* Python 3 has a print function */