media: cx18: remove redundant zero check on retval

The check for a zero retval is redundant as all paths that lead to
this point have set retval to an error return value that is non-zero.
Remove the redundant check.

Detected by CoverityScan, CID#102589 ("Logically dead code")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/pci/cx18/cx18-driver.c

@@ -1134,8 +1134,6 @@ free_mem:
 free_workqueues:
 	destroy_workqueue(cx->in_work_queue);
 err:
-	if (retval == 0)
-		retval = -ENODEV;
 	CX18_ERR("Error %d on initialization\n", retval);
 
 	v4l2_device_unregister(&cx->v4l2_dev);