mmc: sdhci-of-at91: fix memleak on clk_get failure

sdhci_alloc_host() does its work not using managed infrastructure, so
needs explicit free on error path. Add it where needed.

Cc: <stable@vger.kernel.org>
Fixes: bb5f8ea4 ("mmc: sdhci-of-at91: introduce driver for the Atmel SDMMC")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/b2a44d5be2e06ff075f32477e466598bb0f07b36.1577961679.git.mirq-linux@rere.qmqm.plSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-of-at91.c

@@ -345,20 +345,23 @@ static int sdhci_at91_probe(struct platform_device *pdev)
 			priv->mainck = NULL;
 		} else {
 			dev_err(&pdev->dev, "failed to get baseclk\n");
-			return PTR_ERR(priv->mainck);
+			ret = PTR_ERR(priv->mainck);
+			goto sdhci_pltfm_free;
 		}
 	}
 
 	priv->hclock = devm_clk_get(&pdev->dev, "hclock");
 	if (IS_ERR(priv->hclock)) {
 		dev_err(&pdev->dev, "failed to get hclock\n");
-		return PTR_ERR(priv->hclock);
+		ret = PTR_ERR(priv->hclock);
+		goto sdhci_pltfm_free;
 	}
 
 	priv->gck = devm_clk_get(&pdev->dev, "multclk");
 	if (IS_ERR(priv->gck)) {
 		dev_err(&pdev->dev, "failed to get multclk\n");
-		return PTR_ERR(priv->gck);
+		ret = PTR_ERR(priv->gck);
+		goto sdhci_pltfm_free;
 	}
 
 	ret = sdhci_at91_set_clks_presets(&pdev->dev);