[PATCH] restore export of do_kern_mount()

vfs_kern_mount() requires having a reference to fs type, which
makes it impossible for module to create procfs, etc. private
mount.  Open-coding is not an option, since e.g. put_filesystem()
is _not_ exported, and for a good reason.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/super.c b/fs/super.c
index 010446d..dc02af0 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -945,6 +945,7 @@
 	put_filesystem(type);
 	return mnt;
 }
+EXPORT_SYMBOL_GPL(do_kern_mount);
 
 struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
 {