b43: allocate receive buffers big enough for max frame len + offset

Otherwise, skb_put inside of dma_rx can fail...

	https://bugzilla.kernel.org/show_bug.cgi?id=32042

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: stable@kernel.org
    void free_descriptor_buffer(struct b43_dmaring *ring,
				struct b43_dmadesc_meta *meta)
{
	if (meta->skb) {
		dev_kfree_skb_any(meta->skb);
		meta->skb = NULL;
	}
}

    void free_descriptor_buffer(struct b43_dmaring *ring,
				struct b43_dmadesc_meta *meta)
{
	if (meta->skb) {
		dev_kfree_skb_any(meta->skb);
		meta->skb = NULL;
	}
}
