Documentation/driver-api: nvdimm: drop doubled word

Drop the doubled word "to".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20200704034502.17199-14-rdunlap@infradead.org


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