fix bug

Author: lukebakken

src/vm_memory_monitor.erl

@@ -143,7 +143,8 @@ get_memory_use(ratio) ->
 -spec get_process_memory() -> Bytes :: integer().
 get_process_memory() ->
     try
-        get_memory_use(bytes)
+        {ProcMem, _} = get_memory_use(bytes),
+        ProcMem
     catch exit:{noproc, Error} ->
         rabbit_log:warning("Memory monitor process not yet started: ~p~n", [Error]),
         get_process_memory_uncached()