Retry the sfdisk command up to 3 times.
Retry the sfdisk command up to 3 times.

Updates the nova baremetal-deploy-helper so that we retry
the fdisk command up to 3 times.

Previously the command would sometimes intermittently fail with
'Device or resource busy' errors. There doesn't seem to be a good way
to check/verify this other than to retry.

Fixes LP Bug #1191084.

Change-Id: I18be73cba9c5bf5a4f9cf229dedc4494666c9b35

bacaldwell/ironic,ramineni/myironic,citrix-openstack-build/ironic,SauloAislan/ironic,naototty/vagrant-lxc-ironic,varunarya10/ironic,rackerlabs/ironic,citrix-openstack-build/ironic,Tehsmash/ironic,dims/ironic,NaohiroTamura/ironic,pshchelo/ironic,faizan-barmawer/openstack_ironic,bacaldwell/ironic,openstack/ironic,dims/ironic,openstack/ironic,ionutbalutoiu/ironic,froyobin/ironic,naterh/ironic,devananda/ironic,ionutbalutoiu/ironic,debayanray/ironic_backup,supermari0/ironic,redhat-openstack/ironic,JioCloud/ironic,pshchelo/ironic,rdo-management/ironic,SauloAislan/ironic,NaohiroTamura/ironic,hpproliant/ironic,naototty/vagrant-lxc-ironic,Tan0/ironic