Mirror MS_KERNMOUNT in ->mnt_flags

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/super.c b/fs/super.c
index 903896e..f35ac60 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -937,6 +937,9 @@
 	if (!mnt)
 		goto out;
 
+	if (flags & MS_KERNMOUNT)
+		mnt->mnt_flags = MNT_INTERNAL;
+
 	if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
 		secdata = alloc_secdata();
 		if (!secdata)