mmc: alcor: fix return value check of mmc_add_host()

mmc_add_host() may return error, if we ignore its return value, the memory
that allocated in mmc_alloc_host() will be leaked and it will lead a kernel
crash because of deleting not added device in the remove path.

So fix this by checking the return value and calling mmc_free_host() in the
error path.

Fixes: c5413ad8 ("mmc: add new Alcor Micro Cardreader SD/MMC driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221101063023.1664968-2-yangyingliang@huawei.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/alcor.c

@@ -1114,7 +1114,10 @@ static int alcor_pci_sdmmc_drv_probe(struct platform_device *pdev)
 	alcor_hw_init(host);
 
 	dev_set_drvdata(&pdev->dev, host);
-	mmc_add_host(mmc);
+	ret = mmc_add_host(mmc);
+	if (ret)
+		goto free_host;
+
 	return 0;
 
 free_host: