nvme: Remove unused return code from nvme_delete_ctrl_sync

The return code of nvme_delete_ctrl_sync is never used, so change it to
void.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/core.c

@@ -192,21 +192,16 @@ int nvme_delete_ctrl(struct nvme_ctrl *ctrl)
 }
 EXPORT_SYMBOL_GPL(nvme_delete_ctrl);
 
-static int nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl)
+static void nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl)
 {
-	int ret = 0;
-
 	/*
 	 * Keep a reference until nvme_do_delete_ctrl() complete,
 	 * since ->delete_ctrl can free the controller.
 	 */
 	nvme_get_ctrl(ctrl);
-	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_DELETING))
-		ret = -EBUSY;
-	if (!ret)
+	if (nvme_change_ctrl_state(ctrl, NVME_CTRL_DELETING))
 		nvme_do_delete_ctrl(ctrl);
 	nvme_put_ctrl(ctrl);
-	return ret;
 }
 
 static inline bool nvme_ns_has_pi(struct nvme_ns *ns)