RDMA/srpt: Add a newline when printing parameter 'srpt_service_guid' by sysfs

When I cat module parameter 'srpt_service_guid', it displays as follows.
It is better to add a newline for easy reading.

[root@hulk-202 ~]# cat /sys/module/ib_srpt/parameters/srpt_service_guid
0x0205cdfffe8346b9[root@hulk-202 ~]#

Link: https://lore.kernel.org/r/1589182629-27743-1-git-send-email-wangxiongfeng2@huawei.com


Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>