opusparse: remove unneeded statement

commit da5c41930c removed the two uses of the
new value of data:
  channels = opus_packet_get_nb_channels (data);
  bandwidth = opus_packet_get_bandwidth (data);

Since then, data isn't being used between incrementing it by packet_offset
and going out of scope. Removing this uneeded statement.

ext/opus/gstopusparse.c

@@ -200,7 +200,6 @@ gst_opus_parse_handle_frame (GstBaseParse * base,
       }
 
       packet_offset = 8;
-      data += packet_offset;
 
       /* for ad hoc framing, heed the framing, so we eat any padding */
       payload_offset = packet_size;