Input: psmouse - add a newline when printing 'proto' by sysfs

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

root@syzkaller:~# cat /sys/module/psmouse/parameters/proto
autoroot@syzkaller:~#

Signed-off-by: Xiongfeng Wang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/mouse/psmouse-base.c

···
 {
 	int type = *((unsigned int *)kp->arg);
 
-	return sprintf(buffer, "%s", psmouse_protocol_by_type(type)->name);
+	return sprintf(buffer, "%s\n", psmouse_protocol_by_type(type)->name);
 }
 
 static int __init psmouse_init(void)