illumos gate

For 'zdb <dataset> <objnum>' zdb only outputs information about the given
object, but if <dataset> is actually a pool name (i.e. does not contain '/' or
'@') it starts down the code path that prints all information about the entire
pool (e.g. metaslabs, deferred free lists) and tries to find the given object
number in EVERY dataset in the entire pool, which ends up causing the command
to fail pretty much all the time since the object number probably doesn't exist
in at least one file system. If a user uses that command format I imagine what
they actually want is only information about the given object in the MOS, I
don't see how the old output could possibly have been useful to anyone.