bcache: fix typo in code comments of closure_return_with_destructor()

The code comments of closure_return_with_destructor() in closure.h makrs
function name as closure_return(). This patch fixes this type with the
correct name - closure_return_with_destructor.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/closure.h

@@ -345,7 +345,8 @@ do {									\
 } while (0)
 
 /**
- * closure_return - finish execution of a closure, with destructor
+ * closure_return_with_destructor - finish execution of a closure,
+ *				    with destructor
  *
  * Works like closure_return(), except @destructor will be called when all
  * outstanding refs on @cl have been dropped; @destructor may be used to safely