MFC r232303:

MFC r232303:
In null_reclaim(), assert that reclaimed vnode is fully constructed,
instead of accepting half-constructed vnode. Previous code cannot decide
what to do with such vnode anyway, and although processing it for hash
removal, paniced later when getting rid of nullfs reference on lowervp.

While there, remove initializations from the declaration block.

git-svn-id: svn://svn.freebsd.org/base/stable/9@232645 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f