MFC 314382,314483-314485
314382
hyperv/hn: Simplify RNDIS packet data offset calculation. Sponsored by: Microsoft Differential Revision: https://reviews.freebsd.org/D9699
314483
hyperv/hn: Simplify RNDIS packet total length calculation. Sponsored by: Microsoft Differential Revision: https://reviews.freebsd.org/D9712
314484
hyperv/hn: Make sure that RNDIS packet message is at least 4B aligned. Sponsored by: Microsoft Differential Revision: https://reviews.freebsd.org/D9713
314485
hyperv/hn: Misaligned chimney sending buffers should not be used Sponsored by: Microsoft Differential Revision: https://reviews.freebsd.org/D9714