mmc: alcor: Fix a resource leak in the error path for ->probe()

If devm_request_threaded_irq() fails, the allocated struct mmc_host needs
to be freed via calling mmc_free_host(), so let's do that.

Fixes: c5413ad8 ("mmc: add new Alcor Micro Cardreader SD/MMC driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/20200426202355.43055-1-christophe.jaillet@wanadoo.fr
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/alcor.c

@@ -1104,7 +1104,7 @@ static int alcor_pci_sdmmc_drv_probe(struct platform_device *pdev)
 
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to get irq for data line\n");
-		return ret;
+		goto free_host;
 	}
 
 	mutex_init(&host->cmd_mutex);
@@ -1116,6 +1116,10 @@ static int alcor_pci_sdmmc_drv_probe(struct platform_device *pdev)
 	dev_set_drvdata(&pdev->dev, host);
 	mmc_add_host(mmc);
 	return 0;
+
+free_host:
+	mmc_free_host(mmc);
+	return ret;
 }
 
 static int alcor_pci_sdmmc_drv_remove(struct platform_device *pdev)