builder/qemu: document run_once is gone (but keep it around for compat)

builder/qemu/builder.go

@@ -80,6 +80,8 @@ type config struct {
 	VNCPortMin      uint       `mapstructure:"vnc_port_min"`
 	VNCPortMax      uint       `mapstructure:"vnc_port_max"`
 	VMName          string     `mapstructure:"vm_name"`
+
+	// TODO(mitchellh): deprecate
 	RunOnce         bool       `mapstructure:"run_once"`
 
 	RawBootWait        string `mapstructure:"boot_wait"`
@@ -397,11 +399,6 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		},
 		&stepBootWait{},
 		&stepTypeBootCommand{},
-		
-		
-	}
-
-	steps = append(steps,
 		&common.StepConnectSSH{
 			SSHAddress:     sshAddress,
 			SSHConfig:      sshConfig,
@@ -409,7 +406,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		},
 		new(common.StepProvision),
 		new(stepShutdown),
-	)
+	}
 
 	// Setup the state bag
 	state := new(multistep.BasicStateBag)

website/source/docs/builders/qemu.html.markdown

@@ -199,16 +199,6 @@ Optional:
   By default this is "output-BUILDNAME" where "BUILDNAME" is the name
   of the build.
 
-* `run_once` (boolean) - When set to true, run_once causes the builder to run
-  Qemu only once, rather than twice. Normally (default false) the builder
-  will run Qemu once for an initial OS install, then switch the CDROM device
-  and boot device for a second run. In that case, Packer does not wait for
-  SSH connections until the second power up of the VM. This approach is often
-  necessary in Linux distribution installs. However, in many Windows unattended
-  installs, the setup handles reboots and dealing with the CDROM as the boot
-  device. With care, a power-down/power-up setting (run_once is set to false)
-  could work if the unattended install is set to restart into audit mode.
-
 * `shutdown_command` (string) - The command to use to gracefully shut down
   the machine once all the provisioning is done. By default this is an empty
   string, which tells Packer to just forcefully shut down the machine.