Minor fixup.  maxlen is already known.
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 3c8e025..cef92c0 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -399,7 +399,7 @@
     if (it == NULL)
         return NULL;
 
-    if (deque->maxlen == 0)
+    if (maxlen == 0)
         return consume_iterator(it);
 
     iternext = *Py_TYPE(it)->tp_iternext;
@@ -463,7 +463,7 @@
     if (it == NULL)
         return NULL;
 
-    if (deque->maxlen == 0)
+    if (maxlen == 0)
         return consume_iterator(it);
 
     iternext = *Py_TYPE(it)->tp_iternext;