drm/amdgpu/dm: Do not throw an error for a display with no audio

An old display with no audio may not have an EDID with a CEA block, or
it may simply be too old to support audio. This is not a driver error,
so don't flag it as such.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112140
References: ae2a3495 ("drm/amd: be quiet when no SAD block is found")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c

@@ -97,8 +97,6 @@ enum dc_edid_status dm_helpers_parse_edid_caps(
 			(struct edid *) edid->raw_edid);
 
 	sad_count = drm_edid_to_sad((struct edid *) edid->raw_edid, &sads);
-	if (sad_count < 0)
-		DRM_ERROR("Couldn't read SADs: %d\n", sad_count);
 	if (sad_count <= 0)
 		return result;