给定程序中，函数fun的功能是将不带头结点的单向链表逆置，即若原链表中从头到尾结点数据域依次为：2、4、6、8、10，逆置后，从头至尾结点数据域依次为：10、8、6、4、2。

请在程序的下划线处填入正确的内容并把下划线删除，使程序得出正确的结果。

-A given program, function fun is the function of the node will not take the lead against the home one-way linked list, that if the original list in the node data field from start to finish were: 2,4,6,8,10, inverse set, the node data field from start to finish were: 10,8,6,4,2. Please fill in the application of an underscore at the right content and to remove the underscore, so that the program reach the right result.