EDAC/highbank: Fix memory leak in highbank_mc_probe()

When devres_open_group() fails, it returns -ENOMEM without freeing memory
allocated by edac_mc_alloc().

Call edac_mc_free() on the error handling path to avoid a memory leak.

  [ bp: Massage commit message. ]

Fixes: a1b01ed ("edac: add support for Calxeda highbank memory controller")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20221229054825.1361993-1-linmq006@gmail.com

Author: Yuuoniy

drivers/edac/highbank_mc_edac.c

@@ -174,8 +174,10 @@ static int highbank_mc_probe(struct platform_device *pdev)
 	drvdata = mci->pvt_info;
 	platform_set_drvdata(pdev, mci);
 
-	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL))
-		return -ENOMEM;
+	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
+		res = -ENOMEM;
+		goto free;
+	}
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!r) {
@@ -243,6 +245,7 @@ static int highbank_mc_probe(struct platform_device *pdev)
 	edac_mc_del_mc(&pdev->dev);
 err:
 	devres_release_group(&pdev->dev, NULL);
+free:
 	edac_mc_free(mci);
 	return res;
 }