dm cache: Remove unused dm_cache_size

dm_cache_size() has been unused since the original commit
c6b4fcbad044 ("dm: add cache target")

Remove it.

Signed-off-by: Dr. David Alan Gilbert <[e-mail]>
Signed-off-by: Mikulas Patocka <[e-mail]>

drivers/md/dm-cache-metadata.c

···
 	return r;
 }
 
-int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result)
-{
-	READ_LOCK(cmd);
-	*result = cmd->cache_blocks;
-	READ_UNLOCK(cmd);
-
-	return 0;
-}
-
 static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
 {
 	int r;

drivers/md/dm-cache-metadata.h

···
  * origin blocks to map to.
  */
 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size);
-int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result);
 
 int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
 				   sector_t discard_block_size,