This adds the menu item to rename a dive computer (ie create a nickname
for it) when right-clicking on the dive computer name of a dive computer
that has a serial number (indicated by having a non-zero ->deviceid).
It is nonfunctional because it's really just the skeleton code: it needs
the UI to actually ask for a new nickname, and then it needs to actually
do the proper "create_device_node(model,serial,nickname)" to set it (or
remove the nickname if empty).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>