drm/edid: fix length check when adding extra 3D modes

Signed-off-by: Thomas Wood <thomas.wood@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_edid.c

@@ -2674,7 +2674,7 @@ static int add_3d_struct_modes(struct drm_connector *connector, u16 structure,
 	int modes = 0;
 	u8 cea_mode;
 
-	if (video_db == NULL || video_index > video_len)
+	if (video_db == NULL || video_index >= video_len)
 		return 0;
 
 	/* CEA modes are numbered 1..127 */