[PATCH net-next] 9p: mark expected switch fall-through

["Gustavo A. R. Silva" <gustavo@embeddedor.com>]

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

This patch fixes the following warning:

net/9p/trans_xen.c:514:6: warning: this statement may fall through [-Wimplicit-fallthrough=]

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

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

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 net/9p/trans_xen.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index e2fbf3677b9b..29420ebb8f07 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -513,7 +513,7 @@ static void xen_9pfs_front_changed(struct xenbus_device *dev,
 	case XenbusStateClosed:
 		if (dev->state == XenbusStateClosed)
 			break;
-		/* Missed the backend's CLOSING state -- fallthrough */
+		/* fall through - Missed the backend's CLOSING state */
 	case XenbusStateClosing:
 		xenbus_frontend_closed(dev);
 		break;
-- 
2.20.1