OvmfPkg/VirtioFsDxe: submit the FUSE_INIT request to the device

OvmfPkg/VirtioFsDxe: submit the FUSE_INIT request to the device

Submit the FUSE_INIT request to the Virtio Filesystem device, for starting
the FUSE session.

The FUSE_INIT request is logged by the virtio-fs daemon, with this patch
applied, when (for example) using the "CONNECT" UEFI shell command.

Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-9-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>