sunrpc: add missing newline when printing parameter 'auth_hashtable_size' by sysfs

When I cat parameter
'/sys/module/sunrpc/parameters/auth_hashtable_size', it displays as
follows. It is better to add a newline for easy reading.

[root@hulk-202 ~]# cat /sys/module/sunrpc/parameters/auth_hashtable_size
16[root@hulk-202 ~]#

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>