media: intel/ipu6: fix error pointer dereference

commit 8dd088b upstream.

In a error path isp->psys is confirmed to be an error pointer not NULL so
this condition is true and the error pointer is dereferenced. So isp-psys
should be set to NULL before going to out_ipu6_bus_del_devices.

Detected by Smatch:
drivers/media/pci/intel/ipu6/ipu6.c:690 ipu6_pci_probe() error:
'isp->psys' dereferencing possible ERR_PTR()

Fixes: 25fedc0 ("media: intel/ipu6: add Intel IPU6 PCI device driver")
Cc: stable@vger.kernel.org
Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
[Sakari Ailus: Fix commit message.]
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Ethan Tidmore

drivers/media/pci/intel/ipu6/ipu6.c

@@ -685,7 +685,7 @@ static int ipu6_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 out_ipu6_rpm_put:
 	pm_runtime_put_sync(&isp->psys->auxdev.dev);
 out_ipu6_bus_del_devices:
-	if (isp->psys) {
+	if (!IS_ERR_OR_NULL(isp->psys)) {
 		ipu6_cpd_free_pkg_dir(isp->psys);
 		ipu6_buttress_unmap_fw_image(isp->psys, &isp->psys->fw_sgt);
 	}