K 10 svn:author V 6 dteske K 8 svn:date V 27 2013-12-16T19:51:11.024156Z K 7 svn:log V 503 Fix a long-standing edge-case that would result in a ghosted `zroot' pool and subsequent headaches caused by multiple pools with the same name. Specifically, blast away any labels on the designated swap partition. Problem was when you install to a given layout *with* swap and then turn around and re-install the same layout *without* swap (we weren't doing a labelclear for the swap device, so would end up with an "UNAVAIL" status zroot pool that may only exist in the pool cache). MFC after: 3 days END