Perform Boot Node Failback

Bring a failed primary boot node online as the new backup boot node without doing a full system boot.

When a primary boot node fails and a secondary node takes over, bring the primary node back online without doing a full system boot. An xtbootsys --reboot command is prohibited on the boot node. Therefore, enter several commands to reintroduce a failed primary node to the system as the new backup boot node.

Shut down the primary boot node.
```
smw# xtcli shutdown primary_id
```
Bounce the primary boot node.
```
smw# xtbounce -s primary_id
```
Boot the primary boot node.
```
smw# xtcli boot DEFAULT primary_id
```