hyperv: Remove extra allocated space for recv_pkt_list elements

The receive code path doesn't use the page buffer, so remove the
extra allocated space here.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>