pnfs/blocklayout: remove some debugging

The kbuild test robot complained that we got the printk format wrong.
Let's just kill these printks instead of fixing them as there is not
point after the initial tree algorithm debugging.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>