smb: client: Avoid a dozen -Wflex-array-member-not-at-end warnings

-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 corresponding
structure. Notice that struct smb2_file_all_info is a flexible
structure, this is a structure that contains a flexible-array
member.

Fix the following warnings:

12 fs/smb/client/cached_dir.h:51:35: 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>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: GustavoARSilva

fs/smb/client/cached_dir.h

@@ -48,8 +48,10 @@ struct cached_fid {
 	struct dentry *dentry;
 	struct work_struct put_work;
 	struct work_struct close_work;
-	struct smb2_file_all_info file_all_info;
 	struct cached_dirents dirents;
+
+	/* Must be last as it ends in a flexible-array member. */
+	struct smb2_file_all_info file_all_info;
 };
 
 /* default MAX_CACHED_FIDS is 16 */