ext4: convert EXT4_FLAGS_* defines to enum

Do away with the defines and use an enum as it's cleaner.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250122114130.229709-2-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Author: LiBaokun96

fs/ext4/ext4.h

@@ -2235,9 +2235,11 @@ extern int ext4_feature_set_ok(struct super_block *sb, int readonly);
 /*
  * Superblock flags
  */
-#define EXT4_FLAGS_RESIZING	0
-#define EXT4_FLAGS_SHUTDOWN	1
-#define EXT4_FLAGS_BDEV_IS_DAX	2
+enum {
+	EXT4_FLAGS_RESIZING,	/* Avoid superblock update and resize race */
+	EXT4_FLAGS_SHUTDOWN,	/* Prevent access to the file system */
+	EXT4_FLAGS_BDEV_IS_DAX,	/* Current block device support DAX */
+};
 
 static inline int ext4_forced_shutdown(struct super_block *sb)
 {