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>

drivers/char/ipmi/ipmi_msghandler.c

@@ -89,19 +89,19 @@ static int panic_op_read_handler(char *buffer, const struct kernel_param *kp)
 {
 	switch (ipmi_send_panic_event) {
 	case IPMI_SEND_PANIC_EVENT_NONE:
-		strcpy(buffer, "none");
+		strcpy(buffer, "none\n");
 		break;
 
 	case IPMI_SEND_PANIC_EVENT:
-		strcpy(buffer, "event");
+		strcpy(buffer, "event\n");
 		break;
 
 	case IPMI_SEND_PANIC_EVENT_STRING:
-		strcpy(buffer, "string");
+		strcpy(buffer, "string\n");
 		break;
 
 	default:
-		strcpy(buffer, "???");
+		strcpy(buffer, "???\n");
 		break;
 	}