Documentation/admin-guide: pnfs-block-server: drop doubled word

Drop the doubled word "with".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
Link: https://lore.kernel.org/r/20200704032020.21923-7-rdunlap@infradead.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>