CVE-2026-23286 atm: lec: fix null-ptr-deref in lec_arp_clear_vccs

In the Linux kernel, the following vulnerability has been resolved: atm: lec: fix null-ptr-deref in lecarpclearvccs syzkaller reported a null-ptr-deref in lecarpclearvccs. This issue can be easily reproduced using the syzkaller reproducer. In the ATM LANE LAN Emulation module, the same atmvcc can...