From: Arnd Bergmann <arnd@arndb.de>

lockevent_read() has a __weak definition and the only caller in
kernel/locking/lock_events.c, plus a strong definition in qspinlock_stat.h
that overrides it, but no other declaration. This causes a W=1
warning:

kernel/locking/lock_events.c:61:16: error: no previous prototype for 'lockevent_read' [-Werror=missing-prototypes]

Add shared prototype to avoid the warnings.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 kernel/locking/lock_events.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/locking/lock_events.h b/kernel/locking/lock_events.h
index 8c7e7d25f09c..a6016b91803d 100644
--- a/kernel/locking/lock_events.h
+++ b/kernel/locking/lock_events.h

@@ -57,4 +57,8 @@ static inline void __lockevent_add(enum lock_events event, int inc)
 #define lockevent_cond_inc(ev, c)
 
 #endif /* CONFIG_LOCK_EVENT_COUNTS */
+
+ssize_t lockevent_read(struct file *file, char __user *user_buf,
+		       size_t count, loff_t *ppos);
+
 #endif /* __LOCKING_LOCK_EVENTS_H */

-- 
2.39.2