OvmfPkg/VirtioScsiDxe: add helper to create a fake host adapter error

OvmfPkg/VirtioScsiDxe: add helper to create a fake host adapter error

When virtio request fails we return EFI_DEVICE_ERROR, as per the spec
EFI_EXT_SCSI_PASS_THRU_PROTOCOL.PassThru() member function is required
to implement elaborated error reporting.

The patch refactors out entire block of the code that creates the host
adapter error into a separate helper function (ReportHostAdapterError).

Suggested-by: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
[lersek@redhat.com: fix style & typo in ReportHostAdapterError() comment]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>