Add break or pseudo keyword fallthrough to address violations of
MISRA C Rule 16.3.

No functional change.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
---
 xen/arch/x86/traps.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 9906e874d5..cbcec3fafb 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1186,6 +1186,7 @@ void cpuid_hypervisor_leaves(const struct vcpu *v, uint32_t leaf,
 
     default:
         ASSERT_UNREACHABLE();
+        break;
     }
 }
 
@@ -1748,6 +1749,7 @@ static void io_check_error(const struct cpu_user_regs *regs)
     {
     case 'd': /* 'dom0' */
         nmi_hwdom_report(_XEN_NMIREASON_io_error);
+        fallthrough;
     case 'i': /* 'ignore' */
         break;
     default:  /* 'fatal' */
@@ -1768,6 +1770,7 @@ static void unknown_nmi_error(const struct cpu_user_regs *regs,
     {
     case 'd': /* 'dom0' */
         nmi_hwdom_report(_XEN_NMIREASON_unknown);
+        fallthrough;
     case 'i': /* 'ignore' */
         break;
     default:  /* 'fatal' */
-- 
2.34.1