const: make struct super_block::s_qcop 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>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7ffb62e..df539ba 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -985,7 +985,7 @@
 	.destroy_dquot	= dquot_destroy,
 };
 
-static struct quotactl_ops ext4_qctl_operations = {
+static const struct quotactl_ops ext4_qctl_operations = {
 	.quota_on	= ext4_quota_on,
 	.quota_off	= vfs_quota_off,
 	.quota_sync	= vfs_quota_sync,