Additional data type ops: deinit.

While unloading cas_cache module, volume types were deinitialized, although core
pool still wasn't empty. Now this deinitialization can be done after removing
cores from core pool, and before context is freed.

Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>

modules/cas_cache/volume/vol_block_dev_bottom.h

@@ -21,6 +21,4 @@ int block_dev_try_get_io_class(struct bio *bio, int *io_class);
 
 int block_dev_init(void);
 
-void block_dev_deinit(void);
-
 #endif /* __VOL_BLOCK_DEV_BOTTOM_H__ */