headers: Remove some left-over license text

Remove a left-over from commit 2874c5fd ("treewide: Replace GPLv2
boilerplate/reference with SPDX - rule 152")

There is no need for an empty "License:".
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/0e5ff727626b748238f4b78932f81572143d8f0b.1662896317.git.christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/if_pppol2tp.h

@@ -4,8 +4,6 @@
  *
  * This file supplies definitions required by the PPP over L2TP driver
  * (l2tp_ppp.c).  All version information wrt this file is located in l2tp_ppp.c
- *
- * License:
  */
 #ifndef __LINUX_IF_PPPOL2TP_H
 #define __LINUX_IF_PPPOL2TP_H

include/linux/if_pppox.h

@@ -5,8 +5,6 @@
  *
  * This file supplies definitions required by the PPP over Ethernet driver
  * (pppox.c).  All version information wrt this file is located in pppox.c
- *
- * License:
  */
 #ifndef __LINUX_IF_PPPOX_H
 #define __LINUX_IF_PPPOX_H