If build_skb fails the memory associated with the ring buffer is freed but
the ri->data member is not zeroed in this case. This causes a double-free
of this memory in tg3_free_rings->... path. The patch moves this block after
setting ri->data to NULL.
It would be nice to fix this bug also in stable >= v3.4 trees.
Cc: Nithin Nayak Sujir <nsujir@broadcom.com> Cc: Michael Chan <mchan@broadcom.com> Signed-off-by: Ivan Vecera <ivecera@redhat.com> Acked-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>