Chang device name using tmsh

Confirmed works in 11.5.1 HF7

From Bash (same works inside tmsh without tmsh preceding the command):

 tmsh mv cm device  
 tmsh mv cm device initial.device.name new.device.name

A few services restarted in my case and the device name was now changed.

NOTE: This does not impact the hostname... that is:

 tmsh modify sys global-settings hostname 
 OR
 tmsh modify cm device  hostname