[PATCH] time: Mark expected switch fall-throughs

["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 warnings:

kernel/time/hrtimer.c: In function ‘hrtimer_fixup_activate’:
./include/linux/compiler.h:77:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
 # define unlikely(x) __builtin_expect(!!(x), 0)
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
./include/asm-generic/bug.h:125:2: note: in expansion of macro ‘unlikely’
  unlikely(__ret_warn_on);     \
  ^~~~~~~~
kernel/time/hrtimer.c:366:3: note: in expansion of macro ‘WARN_ON’
   WARN_ON(1);
   ^~~~~~~
kernel/time/hrtimer.c:368:2: note: here
  default:
  ^~~~~~~

kernel/time/timer.c: In function ‘timer_fixup_activate’:
./include/linux/compiler.h:77:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
 # define unlikely(x) __builtin_expect(!!(x), 0)
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
./include/asm-generic/bug.h:125:2: note: in expansion of macro ‘unlikely’
  unlikely(__ret_warn_on);     \
  ^~~~~~~~
kernel/time/timer.c:649:3: note: in expansion of macro ‘WARN_ON’
   WARN_ON(1);
   ^~~~~~~
kernel/time/timer.c:651:2: note: here
  default:
  ^~~~~~~

kernel/time/tick-broadcast.c: In function ‘tick_broadcast_control’:
kernel/time/tick-broadcast.c:377:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
   tick_broadcast_forced = 1;
   ~~~~~~~~~~~~~~~~~~~~~~^~~
kernel/time/tick-broadcast.c:378:2: note: here
  case TICK_BROADCAST_ON:
  ^~~~

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>
---
 kernel/time/hrtimer.c        | 1 +
 kernel/time/tick-broadcast.c | 1 +
 kernel/time/timer.c          | 1 +
 3 files changed, 3 insertions(+)

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 0f5f96075110..5fc8c8add815 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -364,6 +364,7 @@ static bool hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
 	switch (state) {
 	case ODEBUG_STATE_ACTIVE:
 		WARN_ON(1);
+		/* fall through */
 
 	default:
 		return false;
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 803fa67aace9..ee834d4fb814 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -375,6 +375,7 @@ void tick_broadcast_control(enum tick_broadcast_mode mode)
 	switch (mode) {
 	case TICK_BROADCAST_FORCE:
 		tick_broadcast_forced = 1;
+		/* fall through */
 	case TICK_BROADCAST_ON:
 		cpumask_set_cpu(cpu, tick_broadcast_on);
 		if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_mask)) {
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 6eb7cc4b6d52..b1425b7d84d5 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -647,6 +647,7 @@ static bool timer_fixup_activate(void *addr, enum debug_obj_state state)
 
 	case ODEBUG_STATE_ACTIVE:
 		WARN_ON(1);
+		/* fall through */
 
 	default:
 		return false;
-- 
2.20.1