const: make struct super_block::dq_op const

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/fs.h

@@ -1318,7 +1318,7 @@ struct super_block {
 	unsigned long long	s_maxbytes;	/* Max file size */
 	struct file_system_type	*s_type;
 	const struct super_operations	*s_op;
-	struct dquot_operations	*dq_op;
+	const struct dquot_operations	*dq_op;
  	struct quotactl_ops	*s_qcop;
 	const struct export_operations *s_export_op;
 	unsigned long		s_flags;

include/linux/quotaops.h

@@ -135,7 +135,7 @@ static inline int sb_any_quota_active(struct super_block *sb)
 /*
  * Operations supported for diskquotas.
  */
-extern struct dquot_operations dquot_operations;
+extern const struct dquot_operations dquot_operations;
 extern struct quotactl_ops vfs_quotactl_ops;
 
 #define sb_dquot_ops (&dquot_operations)