batman-adv: check return value of pskb_trim_rcsum()

Reported-by: Sven Eckelmann <[email protected]>
Signed-off-by: Marek Lindner <[email protected]>
Acked-by: Martin Hundebøll <[email protected]>
Signed-off-by: Antonio Quartulli <[email protected]>
1 file changed