typo fix: declaration required for VACPP not EMX+gcc
diff --git a/Python/thread_os2.h b/Python/thread_os2.h
index 69bcd2c..738976a 100644
--- a/Python/thread_os2.h
+++ b/Python/thread_os2.h
@@ -230,7 +230,7 @@
 
 void PyThread_release_lock(PyThread_type_lock aLock)
 {
-#if defined(PYCC_GCC)
+#if !defined(PYCC_GCC)
   type_os2_lock lock = (type_os2_lock)aLock;
 #endif