MFC 303284,303329,303361,303362,303366,303368-303370

MFC 303284,303329,303361,303362,303366,303368-303370

303284
    hyperv/vmbus: Move bufring info definition to vmbus_brvar.h

    Sponsored by:   Microsoft OSTC
    Differential Revision:  https://reviews.freebsd.org/D7282

303329
    hyperv/vmbus: Nuke unnecessary accessor functions.

    Sponsored by:   Microsoft OSTC
    Differential Revision:  https://reviews.freebsd.org/D7303

303361
    hyperv/vmbus: Initialize RX/TX bufring mutex at channel creation time

    Sponsored by:   Microsoft OSTC
    Differential Revision:  https://reviews.freebsd.org/D7312

303362
    hyperv/vmbus: Use different struct for RX/TX bufring.

    So that they can use suitable MP synchronization mechanism.

    While I'm here change the bufring init/read/write function names.

    Sponsored by:   Microsoft
    Differential Revision:  https://reviews.freebsd.org/D7313

303366
    hyperv/vmbus: Update comment for bufring

    Sponsored by:   Microsoft
    Differential Revision:  https://reviews.freebsd.org/D7314

303368
    hyperv/vmbus: Cleanup TX bufring write process.

    Sponsored by:   Microsoft
    Differential Revision:  https://reviews.freebsd.org/D7315

303369
    hyperv/vmbus: Stringent RX bufring data length checks.

    Sponsored by:   Microsoft
    Differential Revision:  https://reviews.freebsd.org/D7316

303370
    hyperv/vmbus: Cleanup RX bufring read process.

    Sponsored by:   Microsoft
    Differential Revision:  https://reviews.freebsd.org/D7317

git-svn-id: svn://svn.freebsd.org/base/stable/10@307103 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f