drm/radeon/kms/atom: make sure tables are valid (v2)

Check that atom cmd and data tables are valid
before using them.

(v2)
- fix some whitespace errors noticed by Rafał Miłecki
- check a few more cases

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index d65931d..eca714c 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -368,10 +368,9 @@
 
 	if (rdev->bios) {
 		if (rdev->is_atom_bios) {
-			if (rdev->family >= CHIP_R600)
+			ret = radeon_get_atom_connector_info_from_supported_devices_table(dev);
+			if (ret == false)
 				ret = radeon_get_atom_connector_info_from_object_table(dev);
-			else
-				ret = radeon_get_atom_connector_info_from_supported_devices_table(dev);
 		} else {
 			ret = radeon_get_legacy_connector_info_from_bios(dev);
 			if (ret == false)