One potential user of dpif_port_query_by_name() actually open-coded the
function because it didn't want logging on failure. There was only one
actual caller of the function, which didn't want logging on failure either.
So, clean up by reducing the failure log level to DBG and making the
open-coded version an actual caller.
dpif_id() is often used in error messages, e.g. "dp%u: screwed up". But
soon we will be generalizing the concept of a datapath, so it is better
to have a function that returns a full name, e.g. "%s: screwed up".
Accordingly, this commit replaces dpif_id() by a new function dpif_name()
that does so.
The 'minor' member of struct dpif is used for two different purposes:
for printing in log messages and for encapsulating in NetFlow messages.
The needs in each case are different, so we should break up these uses.
This commit does half of that, by introducing a new function to retrieve
NetFlow ids and using it where appropriate.
With multiple kinds of datapaths, code should not just use
"dp%u" along with dpif_minor() to print a datapath name, because not all
datapaths can sensibly be named that way. We want to use a function
with a name like dpif_get_name() to retrieve a datapath name for printing
to the user, in which case the existing dpif_get_name() function would be
confusing. So rename the existing one to something more explicit.
