libata: acpi: avoid passing NULL to ACPI evaluation method

If ACPI handle for an ATA device is NULL, we shouldn't call
ata_dev_get_GTF as that function will use handle to do some ACPI
evaluation.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/libata-acpi.c

@@ -835,6 +835,7 @@ void ata_acpi_on_resume(struct ata_port *ap)
 		ata_for_each_dev(dev, &ap->link, ALL) {
 			ata_acpi_clear_gtf(dev);
 			if (ata_dev_enabled(dev) &&
+			    ata_dev_acpi_handle(dev) &&
 			    ata_dev_get_GTF(dev, NULL) >= 0)
 				dev->flags |= ATA_DFLAG_ACPI_PENDING;
 		}