blkcg: annotate implicit fall through

There is a plan to build the kernel with -Wimplicit-fallthrough and
this place in the code produced a warning (W=1).

This commit remove the following warning:

  kernel/trace/blktrace.c:725:9: warning: this statement may fall through [-Wimplicit-fallthrough=]

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index fac0ddf8a8e2..e1c6d79fb4cc 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -723,6 +723,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
 #endif
         case BLKTRACESTART:
                 start = 1;
+                /* fall through */
         case BLKTRACESTOP:
                 ret = __blk_trace_startstop(q, start);
                 break;