[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: NAl Viro <viro@zeniv.linux.org.uk>

fs/super.c

@@ -945,6 +945,7 @@ do_kern_mount(const char *fstype, int flags, const char *name, void *data)
 	put_filesystem(type);
 	return mnt;
 }
+EXPORT_SYMBOL_GPL(do_kern_mount);
 
 struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
 {