CVE-2023-52845 tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING

In the Linux kernel, the following vulnerability has been resolved: tipc: Change nlapolicy for bearer-related names to NLANULSTRING syzbot reported the following uninit-value access issue 1: ===================================================== BUG: KMSAN: uninit-value in strlen lib/string.c:418...