6579975 dnode_new_blkid should look before it locks

[jonathan.ad...@sun.com]

Author: Jonathan W Adams <Jonathan.Adams at Sun.COM>
Repository: /hg/onnv/onnv-gate
Latest revision: 396f25bd1f34a545859ef29704fb78a3792148f8
Total changesets: 1
Log message:
6579975 dnode_new_blkid should look before it locks

Files:
        update: usr/src/uts/common/fs/zfs/dbuf.c
        update: usr/src/uts/common/fs/zfs/dnode.c
        update: usr/src/uts/common/fs/zfs/sys/dnode.h