UVI-2021-1001989 net: batman-adv: fix error handling

net: batman-adv: fix error handling This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v4.19.215 by commit fbf150b16a3635634b7dfb7f229d8fcd643c6c51...