constify dentry_operations: autofs, autofs4

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 2a41c2a..74b1469 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -349,13 +349,13 @@
 }
 
 /* For dentries of directories in the root dir */
-static struct dentry_operations autofs4_root_dentry_operations = {
+static const struct dentry_operations autofs4_root_dentry_operations = {
 	.d_revalidate	= autofs4_revalidate,
 	.d_release	= autofs4_dentry_release,
 };
 
 /* For other dentries */
-static struct dentry_operations autofs4_dentry_operations = {
+static const struct dentry_operations autofs4_dentry_operations = {
 	.d_revalidate	= autofs4_revalidate,
 	.d_release	= autofs4_dentry_release,
 };