fix: verity boot overrides SCSI config (microsoft#2262)

When creating HCS doc for SNP UVM with verity boot, the SCSI
controllers are overriden to always have only a single SCSI
controller. This limits the max number of container layers to
64.

Signed-off-by: Maksim An <maksiman@microsoft.com>
Signed-off-by: Heather Garvison <hgarvison@microsoft.com>

internal/uvm/create_lcow.go

@@ -471,16 +471,10 @@ func makeLCOWVMGSDoc(ctx context.Context, opts *OptionsLCOW, uvm *UtilityVM) (_
 		if opts.DmVerityMode {
 			logrus.Debug("makeLCOWVMGSDoc DmVerityMode true")
 			scsiController0 := guestrequest.ScsiControllerGuids[0]
-			doc.VirtualMachine.Devices.Scsi = map[string]hcsschema.Scsi{
-				scsiController0: {
-					Attachments: map[string]hcsschema.Attachment{
-						"0": {
-							Type_:    "VirtualDisk",
-							Path:     dmVerityRootFsFullPath,
-							ReadOnly: true,
-						},
-					},
-				},
+			doc.VirtualMachine.Devices.Scsi[scsiController0].Attachments["0"] = hcsschema.Attachment{
+				Type_:    "VirtualDisk",
+				Path:     dmVerityRootFsFullPath,
+				ReadOnly: true,
 			}
 			uvm.reservedSCSISlots = append(uvm.reservedSCSISlots, scsi.Slot{Controller: 0, LUN: 0})
 		}