[PATCH] arm64: hw_breakpoint: mark expected switch fall-through

[Matteo Croce <mcroce@redhat.com>]

Mark switch cases where we are expecting to fall through,
fixes the following warning:

  CC      arch/arm64/kernel/hw_breakpoint.o
arch/arm64/kernel/hw_breakpoint.c: In function ‘hw_breakpoint_arch_parse’:
arch/arm64/kernel/hw_breakpoint.c:540:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
    if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
       ^
arch/arm64/kernel/hw_breakpoint.c:542:3: note: here
   case 2:
   ^~~~
arch/arm64/kernel/hw_breakpoint.c:544:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
    if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
       ^
arch/arm64/kernel/hw_breakpoint.c:546:3: note: here
   default:
   ^~~~~~~

Signed-off-by: Matteo Croce <mcroce@redhat.com>
---
 arch/arm64/kernel/hw_breakpoint.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index dceb84520948..7d846985b133 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -539,10 +539,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
 			/* Allow single byte watchpoint. */
 			if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
 				break;
+			/* fallthrough */
 		case 2:
 			/* Allow halfword watchpoints and breakpoints. */
 			if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
 				break;
+			/* fallthrough */
 		default:
 			return -EINVAL;
 		}
-- 
2.21.0