No need to double-include config.h


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74854 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Threading.cpp b/lib/System/Threading.cpp
index bc41afe..466c468 100644
--- a/lib/System/Threading.cpp
+++ b/lib/System/Threading.cpp
@@ -11,12 +11,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Config/config.h"
 #include "llvm/System/Threading.h"
 #include "llvm/System/Atomic.h"
 #include "llvm/System/Mutex.h"
 #include "llvm/Config/config.h"
 #include <cassert>
+
 using namespace llvm;
 
 static bool multithreaded_mode = false;