[PATCH][next] fs: namespace: Avoid -Wflex-array-member-not-at-end warning

["Gustavo A. R. Silva" <gustavoars@kernel.org>]

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Move the conflicting declaration to the end of the structure. Notice
that `struct statmount` is a flexible structure --a structure that
contains a flexible-array member.

Fix the following warning:

fs/namespace.c:5329:26: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 fs/namespace.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index 6100e5b962a6..16292ff760c9 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -5326,8 +5326,10 @@ struct kstatmount {
 	struct mnt_idmap *idmap;
 	u64 mask;
 	struct path root;
-	struct statmount sm;
 	struct seq_file seq;
+
+	/* Must be last --ends in a flexible-array member. */
+	struct statmount sm;
 };
 
 static u64 mnt_to_attr_flags(struct vfsmount *mnt)
-- 
2.43.0