Fixing shutdown_command doc for qemu builder
Fixing shutdown_command doc for qemu builder

bryson/packer,timsutton/packer,mitchellh/packer,mitchellh/packer,timsutton/packer,rnaveiras/packer,youhong316/packer,rnaveiras/packer,dave2/packer,tb3088/packer,KohlsTechnology/packer,KohlsTechnology/packer,dave2/packer,dave2/packer,tas50/packer,timsutton/packer,hashicorp/packer,rnaveiras/packer,mitchellh/packer,youhong316/packer,pecigonzalo/packer,dave2/packer,mkuzmin/packer,grubernaut/packer,mkuzmin/packer,tas50/packer,youhong316/packer,paulmey/packer,ricardclau/packer,mkuzmin/packer,hashicorp/packer,tb3088/packer,tas50/packer,KohlsTechnology/packer,pecigonzalo/packer,tb3088/packer,pecigonzalo/packer,rnaveiras/packer,bryson/packer,ricardclau/packer,timsutton/packer,tb3088/packer,ricardclau/packer,hashicorp/packer,bryson/packer,tb3088/packer,grubernaut/packer,dave2/packer,paulmey/packer,pecigonzalo/packer,rnaveiras/packer,grubernaut/packer,grubernaut/packer,bryson/packer,mitchellh/packer,youhong316/packer,mitchellh/packer,grubernaut/packer,ricardclau/packer,ricardclau/packer,ricardclau/packer,mkuzmin/packer,KohlsTechnology/packer,KohlsTechnology/packer,tas50/packer,tb3088/packer,youhong316/packer,youhong316/packer,paulmey/packer,rnaveiras/packer,tas50/packer,mkuzmin/packer,KohlsTechnology/packer,grubernaut/packer,tas50/packer,paulmey/packer,dave2/packer,timsutton/packer,hashicorp/packer,paulmey/packer,timsutton/packer,bryson/packer,bryson/packer,mkuzmin/packer,paulmey/packer