constify dentry_operations: rest

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 577385a..9ced062 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -480,7 +480,7 @@
 	return 1;
 }
 
-static struct dentry_operations rpc_dentry_operations = {
+static const struct dentry_operations rpc_dentry_operations = {
 	.d_delete = rpc_delete_dentry,
 };