NSX: fix nonsensical log trace on update port

Having this at a WARN level makes no sense, especially
because the actually message does not say anything about
a warning condition. Probably a brain fart of some sort.
Make it DEBUG, just because it may come handy to see what
data we're passing.

Change-Id: Ie667018faae587a3adb6b3edda4d9912344cae83
Merge "NSX: fix nonsensical log trace on update port"