ata: ahci_xgene: dereferencing uninitialized pointer in probe

commit 8134233e upstream.

If the call to acpi_get_object_info() fails then "info" hasn't been
initialized.  In that situation, we already know that "version" should
be XGENE_AHCI_V1 so we don't actually need to dereference "info".

Fixes: c9802a4b ('ata: ahci_xgene: Add AHCI Support for 2nd HW version of APM X-Gene SoC AHCI SATA Host controller.')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/ata/ahci_xgene.c

@@ -739,11 +739,11 @@ static int xgene_ahci_probe(struct platform_device *pdev)
 				dev_warn(&pdev->dev, "%s: Error reading device info. Assume version1\n",
 					__func__);
 				version = XGENE_AHCI_V1;
-			}
-			if (info->valid & ACPI_VALID_CID)
+			} else if (info->valid & ACPI_VALID_CID) {
 				version = XGENE_AHCI_V2;
 			}
 		}
+	}
 #endif
 
 	dev_dbg(dev, "VAddr 0x%p Mmio VAddr 0x%p\n", ctx->csr_core,