[PATCH] lockdep: avoid a clang warning

[Arnd Bergmann <arnd@arndb.de>]

Clang warns about a tentative array definition without a length:

kernel/locking/lockdep.c:845:12: error: tentative array definition assumed to have one element [-Werror]

There is no real reason to do this here, so just set the same length as
in the real definition later in the same file.  It has to be hidden in
an #ifdef or annotated __maybe_unused though, to avoid the unused-variable
warning if CONFIG_PROVE_LOCKING is disabled.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 kernel/locking/lockdep.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 21cb81fe6359..35a144dfddf5 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -842,7 +842,9 @@ static bool class_lock_list_valid(struct lock_class *c, struct list_head *h)
 	return true;
 }
 
-static u16 chain_hlocks[];
+#ifdef CONFIG_PROVE_LOCKING
+static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+#endif
 
 static bool check_lock_chain_key(struct lock_chain *chain)
 {
-- 
2.20.0