Drivers: net: hyperv: Get rid of the rndis_filter_packet structure

This structure is redundant; get rid of it make the code little more efficient -
get rid of the unnecessary indirection.

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