Avoid unlocking never-locked objects at the end of functions

Cython/Compiler/Nodes.py

@@ -2187,7 +2187,8 @@ class FuncDefNode(StatNode, BlockNode):
                 code.put_cyxdecref(entry.cname)
 
         for node in lenv.autolocked_nodes:
-            code.putln("Cy_UNLOCK(%s);" % node.result())
+            if node.entry.needs_rlock or node.entry.needs_wlock:
+                code.putln("Cy_UNLOCK(%s);" % node.result())
 
         # Decref any increfed args
         for entry in lenv.arg_entries: