Compile fix: An "int" function had accidentally lost its "return 0;", re-add it.

sql/handler.cc:
  An "int" function should explicitly return a value (Sun compilers insist on it):
  Re-add the original "return 0;" (Heikki 1.82.1.12) which got lost by accident.

sql/handler.cc

@@ -1178,6 +1178,7 @@ int ha_release_temporary_latches(THD *thd)
 #ifdef WITH_INNOBASE_STORAGE_ENGINE
   innobase_release_temporary_latches(thd);
 #endif
+  return 0;
 }