[PATCH] xen/events: fix build

[Juergen Gross <jgross@xxxxxxxx>]

Commit 5f2df45ead7c1195 ("xen/evtchn: rework per event channel lock")
introduced a build failure for NDEBUG builds.

Fixes: 5f2df45ead7c1195 ("xen/evtchn: rework per event channel lock")
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 xen/common/event_channel.c | 2 ++
 xen/include/xen/sched.h    | 2 --
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index eacd96b92f..da85d536f4 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -61,7 +61,9 @@ static inline void evtchn_write_lock(struct evtchn *evtchn)
 {
     write_lock(&evtchn->lock);
 
+#ifndef NDEBUG
     evtchn->old_state = evtchn->state;
+#endif
 }
 
 static inline void evtchn_write_unlock(struct evtchn *evtchn)
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 7251b3ae3e..95f96e7a33 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -114,9 +114,7 @@ struct evtchn
         u16 virq;      /* state == ECS_VIRQ */
     } u;
     u8 priority;
-#ifndef NDEBUG
     u8 old_state;      /* State when taking lock in write mode. */
-#endif
     u8 last_priority;
     u16 last_vcpu_id;
 #ifdef CONFIG_XSM
-- 
2.26.2