const: struct quota_format_ops

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/quota/quota_v1.c

@@ -204,7 +204,7 @@ out:
 	return ret;
 }
 
-static struct quota_format_ops v1_format_ops = {
+static const struct quota_format_ops v1_format_ops = {
 	.check_quota_file	= v1_check_quota_file,
 	.read_file_info		= v1_read_file_info,
 	.write_file_info	= v1_write_file_info,