Quiet down a large log file heavy hitter.

Quiet down a large log file heavy hitter.

This line of code serialized the python structure for the device and throws it
at the log file.  The string is about 90K characters, isn't very useful and we
found that it takes a very large amount of space in the log file causing them
to grow very quickly and fill our log disk.  This change extracts the device
name (e.g.  "tapcdc07af9-8a") and uses that in the log message.

Change-Id: I240eb811445752407583f0fb322ce061acb293b9
Fixes: Bug #1200321