Fix memory leak in _memory_usage

Author: ngoldbaum

stringdtype/stringdtype/src/dtype.c

@@ -246,8 +246,6 @@ stringdtype_new(PyTypeObject *NPY_UNUSED(cls), PyObject *args, PyObject *kwds)
 static void
 stringdtype_dealloc(StringDTypeObject *self)
 {
-    // Need to deallocate all the memory allocated during setitem.
-
     PyArrayDescr_Type.tp_dealloc((PyObject *)self);
 }
 

stringdtype/stringdtype/src/main.c

@@ -64,6 +64,8 @@ _memory_usage(PyObject *NPY_UNUSED(self), PyObject *obj)
 
     } while (iternext(iter));
 
+    NpyIter_Deallocate(iter);
+
     PyObject *ret = PyLong_FromSize_t(memory_usage);
 
     return ret;