util: clean up and expand 802.1QbX negotiation logging
util: clean up and expand 802.1QbX negotiation logging

The existing log messages for this have several problems; there are
two lines of log when one will suffice, they duplicate the function
name in log message (when it's already included by VIR_DEBUG), they're
missing some useful bits, they get logged even when the call is a NOP.

This patch cleans up the problems with those existing logs, and also
adds a new VIR_INFO-level log down at the function that is actually
creating and sending the netlink message that logs *everything* going
into the netlink message (which turns out to be much more useful in
practice for me; I didn't want to eliminate the logs at the existing
location though, in case they are useful in some scenario I'm
unfamiliar with; anyway those logs are remaining at debug level, so it
shouldn't be a bother to anyone).

fabianfreyer/libvirt,jardasgit/libvirt,eskultety/libvirt,andreabolognani/libvirt,eskultety/libvirt,datto/libvirt,olafhering/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jardasgit/libvirt,libvirt/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,crobinso/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,zippy2/libvirt,datto/libvirt,VenkatDatta/libvirt,taget/libvirt,andreabolognani/libvirt,jfehlig/libvirt,taget/libvirt,nertpinx/libvirt,datto/libvirt,nertpinx/libvirt,eskultety/libvirt,libvirt/libvirt,zippy2/libvirt,libvirt/libvirt,taget/libvirt,fabianfreyer/libvirt,taget/libvirt,datto/libvirt,jardasgit/libvirt,crobinso/libvirt,andreabolognani/libvirt,jfehlig/libvirt,zippy2/libvirt,olafhering/libvirt,crobinso/libvirt,taget/libvirt,libvirt/libvirt,nertpinx/libvirt,andreabolognani/libvirt,eskultety/libvirt,datto/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,zippy2/libvirt,olafhering/libvirt,crobinso/libvirt,eskultety/libvirt,nertpinx/libvirt,olafhering/libvirt