[PATCH] filelock: ignore 'lock' argument to for_each_file_lock()

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

When CONFIG_FILE_LOCKING is disabled, ceph causes a warning about
a variable that is only used insode of the for_each_file_lock()
loop:

fs/ceph/locks.c: In function 'ceph_count_locks':
fs/ceph/locks.c:380:27: error: unused variable 'lock' [-Werror=unused-variable]
  380 |         struct file_lock *lock;

Rather than working around this in ceph, change the macro definition
to still contain a reference to the variable in order to shut up the
warning.

Fixes: 75cabec0111b ("filelock: add some new helper functions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/filelock.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/filelock.h b/include/linux/filelock.h
index aabd4bdf7eba..69290173280a 100644
--- a/include/linux/filelock.h
+++ b/include/linux/filelock.h
@@ -283,7 +283,7 @@ static inline void locks_wake_up(struct file_lock *fl)
 {
 }
 
-#define for_each_file_lock(_fl, _head)	while(false)
+#define for_each_file_lock(_fl, _head)	while((void)_fl, false)
 
 static inline void
 locks_free_lock_context(struct inode *inode)
-- 
2.39.2