constify dentry_operations: GFS2

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
index c2ad363..aea4d50 100644
--- a/fs/gfs2/ops_dentry.c
+++ b/fs/gfs2/ops_dentry.c
@@ -108,7 +108,7 @@
 	return 0;
 }
 
-struct dentry_operations gfs2_dops = {
+const struct dentry_operations gfs2_dops = {
 	.d_revalidate = gfs2_drevalidate,
 	.d_hash = gfs2_dhash,
 };