[PATCH] ser_gigaset: mark expected switch fall-through

[Gustavo A. R. Silva]

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warning:

drivers/isdn/gigaset/ser-gigaset.c: In function ‘gigaset_tty_ioctl’:
drivers/isdn/gigaset/ser-gigaset.c:627:3: warning: this statement may fall 
through [-Wimplicit-fallthrough=]
   switch (arg) {
   ^~~~~~
drivers/isdn/gigaset/ser-gigaset.c:638:2: note: here
  default:
  ^~~~~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

Notice that, in this particular case, the code comment is modified
in accordance with what GCC is expecting to find.

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gust...@embeddedor.com>
---
 drivers/isdn/gigaset/ser-gigaset.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/isdn/gigaset/ser-gigaset.c 
b/drivers/isdn/gigaset/ser-gigaset.c
index ab0b63a4d045..e1de8b1a1001 100644
--- a/drivers/isdn/gigaset/ser-gigaset.c
+++ b/drivers/isdn/gigaset/ser-gigaset.c
@@ -633,7 +633,7 @@ gigaset_tty_ioctl(struct tty_struct *tty, struct file *file,
                        flush_send_queue(cs);
                        break;
                }
-               /* Pass through */
+               /* fall through */
 
        default:
                /* pass through to underlying serial device */
-- 
2.20.1