To manually finish an upgrade and continue rebooting nodes that were not rebooted, complete the following steps:
# show slot detail | include "information|Image|State|ver:"
Slot-1 information:
State: Operational
Current State: MASTER
Image Selected: primary
Image Booted: secondary
Primary ver: 31.3.1.22
Secondary ver: 31.3.0.106
Slot-2 information:
State: Operational
Current State: BACKUP (In Sync)
Image Selected: primary
Image Booted: secondary
Primary ver: 31.3.1.22
Secondary ver: 31.3.0.106
Slot-3 information:
State: Operational
Current State: STANDBY
Image Selected: primary
Image Booted: primary
Primary ver: 31.3.1.22
Secondary ver: 31.3.0.106
Slot-4 information:
State: Operational
Current State: STANDBY
Image Selected: primary
Image Booted: secondary
Primary ver: 31.3.1.22
Secondary ver: 31.3.0.106

Note
After each reboot, allow a few minutes for the network to converge before proceeding.