drm/radeon: use variable flags as parameter

To be consistent with amdgpu driver, use "flags" as the parameter because
it is already assigned as "ent->driver_data".
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Wu Hoi Pok <wuhoipok@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_drv.c

@@ -314,7 +314,7 @@ static int radeon_pci_probe(struct pci_dev *pdev,
 	if (ret)
 		goto err_agp;
 
-	ret = drm_dev_register(ddev, ent->driver_data);
+	ret = drm_dev_register(ddev, flags);
 	if (ret)
 		goto err_agp;