firecracker: Add support for v0.15.x

Add support for v0.15.x. Change the drive naming scheme to match
the requirement of v0.15.x

Fixes: kata-containers#1598

Signed-off-by: Manohar Castelino <manohar.r.castelino@intel.com>

virtcontainers/fc.go

@@ -395,7 +395,7 @@ func (fc *firecracker) createDiskPool() error {
 	defer span.Finish()
 
 	for i := 0; i < fcDiskPoolSize; i++ {
-		driveID := "drive-" + strconv.Itoa(i)
+		driveID := "drive_" + strconv.Itoa(i)
 		driveParams := ops.NewPutGuestDriveByIDParams()
 		driveParams.SetDriveID(driveID)
 		isReadOnly := false
@@ -566,7 +566,7 @@ func (fc *firecracker) fcUpdateBlockDrive(drive config.BlockDrive) error {
 
 	// Use the global block index as an index into the pool of the devices
 	// created for firecracker.
-	driveID := "drive-" + strconv.Itoa(drive.Index)
+	driveID := "drive_" + strconv.Itoa(drive.Index)
 	driveParams := ops.NewPatchGuestDriveByIDParams()
 	driveParams.SetDriveID(driveID)