machine: remove StartInstance

StartInstance is not tested and not called by firectl or
firecracker-containerd.  Removing it, but we can add it back if a
use-case surfaces.

Signed-off-by: Samuel Karp <[email protected]>

Author: samuelkarp

machine.go

@@ -518,11 +518,6 @@ func (m *Machine) addVsock(ctx context.Context, dev VsockDevice) error {
 	return nil
 }
 
-// StartInstance starts the Firecracker microVM
-func (m *Machine) StartInstance(ctx context.Context) error {
-	return m.startInstance(ctx)
-}
-
 func (m *Machine) startInstance(ctx context.Context) error {
 	info := models.InstanceActionInfo{
 		ActionType: models.InstanceActionInfoActionTypeInstanceStart,