dm cache: fix typo in 2 comment blocks

Replace neccessarily with necessarily.
Signed-off-by: Steven Lung <1030steven@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-cache-metadata.h

@@ -131,7 +131,7 @@ void dm_cache_dump(struct dm_cache_metadata *cmd);
  * hints will be lost.
  *
  * The hints are indexed by the cblock, but many policies will not
- * neccessarily have a fast way of accessing efficiently via cblock.  So
+ * necessarily have a fast way of accessing efficiently via cblock.  So
  * rather than querying the policy for each cblock, we let it walk its data
  * structures and fill in the hints in whatever order it wishes.
  */

drivers/md/dm-cache-target.c

@@ -2775,7 +2775,7 @@ static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
 
 /*
  * The discard block size in the on disk metadata is not
- * neccessarily the same as we're currently using.  So we have to
+ * necessarily the same as we're currently using.  So we have to
  * be careful to only set the discarded attribute if we know it
  * covers a complete block of the new size.
  */