linux-phytec-fsl

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>