ipmi: add a newline when printing parameter 'panic_op' by sysfs

When I cat ipmi_msghandler parameter 'panic_op' by sysfs, it displays as
follows. It's better to add a newline for easy reading.

root@(none):/# cat /sys/module/ipmi_msghandler/parameters/panic_op
noneroot@(none):/#

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Message-Id: <1599130873-2402-1-git-send-email-wangxiongfeng2@huawei.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>