Switch C++-style C headers with their C equivalents.

The C++ headers define the C functions within the std:: namespace, but
we mainly don't use the std:: namespace for C functions. Therefore we
should include the C headers.

BUG=1833
R=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1917004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4486 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/system_wrappers/source/sort.cc b/webrtc/system_wrappers/source/sort.cc
index c3b61e0..9144a58 100644
--- a/webrtc/system_wrappers/source/sort.cc
+++ b/webrtc/system_wrappers/source/sort.cc
@@ -15,12 +15,13 @@
 
 #include "webrtc/system_wrappers/interface/sort.h"
 
-#include <cassert>
-#include <cstring>  // memcpy
+#include <assert.h>
+#include <string.h>  // memcpy
+
 #include <new>      // nothrow new
 
 #ifdef NO_STL
-#include <cstdlib>      // qsort
+#include <stdlib.h>      // qsort
 #else
 #include <algorithm>    // std::sort
 #include <vector>