[NaCl SDK]: nacl_io: add nacl_io_uninit function.

native_client_sdk/src/libraries/ppapi_simple/ps_main.cc

Index: native_client_sdk/src/libraries/ppapi_simple/ps_main.cc
diff --git a/native_client_sdk/src/libraries/ppapi_simple/ps_main.cc b/native_client_sdk/src/libraries/ppapi_simple/ps_main.cc
index 3b634f99329664df75bfba9541fd7650fe0d2f58..8ab1213e53ce9b5a75fa32b74e1be864f69f8290 100644
--- a/native_client_sdk/src/libraries/ppapi_simple/ps_main.cc
+++ b/native_client_sdk/src/libraries/ppapi_simple/ps_main.cc
@@ -43,5 +43,7 @@ int main(int argc, char* argv[]) {
   // By default, or if not running in the browser we simply run the main
   // entry point directly, on the main thread.
   nacl_io_init();
-  return PSUserMainGet()(argc, argv);
+  int rtn = PSUserMainGet()(argc, argv);
+  nacl_io_uninit();
+  return rtn;
 }