drm/i915/sdvo: Don't write stack garbage into the hbuf

Pass the length returned by hdmi_infoframe_pack_only() to
intel_sdvo_write_infoframe() so that we don't end up writing
stack garbage into the hbuf.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190409144054.24561-7-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/intel_sdvo.c

@@ -1106,7 +1106,7 @@ static bool intel_sdvo_set_avi_infoframe(struct intel_sdvo *intel_sdvo,
 
 	return intel_sdvo_write_infoframe(intel_sdvo, SDVO_HBUF_INDEX_AVI_IF,
 					  SDVO_HBUF_TX_VSYNC,
-					  sdvo_data, sizeof(sdvo_data));
+					  sdvo_data, len);
 }
 
 static void intel_sdvo_get_avi_infoframe(struct intel_sdvo *intel_sdvo,