Fix a Lua stack overflow in the C callback MJLuaCompletionsForWord

Hammerspoon/MJLua.m

@@ -787,19 +787,16 @@ void MJLuaDealloc(void) {
    _lua_stackguard_entry(skin.L);

    [skin pushLuaRef:refTable ref:completionsForWordFn];
    if (!lua_isfunction(skin.L, -1)) {
        HSNSLOG(@"ERROR: MJLuaCompletionsForWord doesn't seem to have a completionsForWordFn");
        _lua_stackguard_exit(skin.L);
        return @[];
    }
    [skin pushNSObject:completionWord];
    if ([skin protectedCallAndError:@"MJLuaCompletionsForWord" nargs:1 nresults:1] == NO) {
        _lua_stackguard_exit(skin.L);
        return @[];
    }

    NSArray *completions = [skin toNSObjectAtIndex:-1];
    lua_pop(skin.L, 1);
    _lua_stackguard_exit(skin.L);
    return [skin toNSObjectAtIndex:-1];
    return completions;
}

// C-Code helper to return current active LuaState. Useful for callbacks to