Remove std:: prefixes from C functions in talk/.

std::memcpy -> memcpy for instance. This change was motivated by a
compile report complaining that std::rand() was used instead of rand(),
probably with a stdlib.h include instead of cstdlib. Use of C functions
without the std:: prefix is a lot more common, so removing std:: to
address this.

BUG=
R=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9559004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5657 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/base/nethelpers.h b/talk/base/nethelpers.h
index a49f48a..5b385bb 100644
--- a/talk/base/nethelpers.h
+++ b/talk/base/nethelpers.h
@@ -30,7 +30,7 @@
 
 #ifdef POSIX
 #include <netdb.h>
-#include <cstddef>
+#include <stddef.h>
 #elif WIN32
 #include <winsock2.h>  // NOLINT
 #endif