selinux: remove secondary ops call to sb_umount

Remove secondary ops call to sb_umount, which is
a noop in capabilities.

Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/selinux/hooks.c

@@ -2543,11 +2543,6 @@ static int selinux_mount(char *dev_name,
 static int selinux_umount(struct vfsmount *mnt, int flags)
 {
 	const struct cred *cred = current_cred();
-	int rc;
-
-	rc = secondary_ops->sb_umount(mnt, flags);
-	if (rc)
-		return rc;
 
 	return superblock_has_perm(cred, mnt->mnt_sb,
 				   FILESYSTEM__UNMOUNT, NULL);