media: intel/ipu6: fix error pointer dereference

media: intel/ipu6: fix error pointer dereference

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: 25fedc021985a ("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>