platform/x86: mlx-platform: Fix copy-paste error in mlxplat_init()

The return value from platform_device_register_resndata() is not checked
correctly. The test is done against a wrong variable. This patch fix it.

Fixes: 0378123c5800 ("platform/x86: mlx-platform: Add mlxreg-fan platform driver activation")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/mlx-platform.c

@@ -1704,8 +1704,8 @@ static int __init mlxplat_init(void)
 					PLATFORM_DEVID_NONE, NULL, 0,
 					mlxplat_fan,
 					sizeof(*mlxplat_fan));
-		if (IS_ERR(priv->pdev_io_regs)) {
-			err = PTR_ERR(priv->pdev_io_regs);
+		if (IS_ERR(priv->pdev_fan)) {
+			err = PTR_ERR(priv->pdev_fan);
 			goto fail_platform_io_regs_register;
 		}
 	}