blk-iocost: Remove unnecessary (void*) conversions

The key pointer is void and hence does not need an explicit cast.
Signed-off-by: Li zeming <zeming@nfschina.com>
Link: https://lore.kernel.org/r/20220919012825.2936-1-zeming@nfschina.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-iocost.c

@@ -1430,7 +1430,7 @@ static int iocg_wake_fn(struct wait_queue_entry *wq_entry, unsigned mode,
 			int flags, void *key)
 {
 	struct iocg_wait *wait = container_of(wq_entry, struct iocg_wait, wait);
-	struct iocg_wake_ctx *ctx = (struct iocg_wake_ctx *)key;
+	struct iocg_wake_ctx *ctx = key;
 	u64 cost = abs_cost_to_cost(wait->abs_cost, ctx->hw_inuse);
 
 	ctx->vbudget -= cost;