Issue #12650: Fix a race condition where a subprocess.Popen could leak
resources (FD/zombie) when killed at the wrong time.
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index e92961a..abd76ee 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -460,7 +460,7 @@
 def _cleanup():
     for inst in _active[:]:
         res = inst._internal_poll(_deadstate=sys.maxint)
-        if res is not None and res >= 0:
+        if res is not None:
             try:
                 _active.remove(inst)
             except ValueError: