ieee802154: hwsim: Fix possible memory leaks

After replacing e->info, it is necessary to free the old einfo.

Fixes: f25da51f

 ("ieee802154: hwsim: add replacement for fakelb")
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Chen Aotian <chenaotian2@163.com>
Link: https://lore.kernel.org/r/20230409022048.61223-1-chenaotian2@163.com


Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>