: Retraction of timestamps - Cleanups

Apologies for this late follow-up. I have spent an entire day going through the patches again, checking again the changes made on Friday.

I had missed one or two instances of skb_get_timestamp, these were better hidden. There are now no more left and the patch set has been compile tested on 5 different machines.

Furthermore, I found a bug in the computation of CCID3 elapsed time when sending feedback, it is one of the older bugs and had not occurred to anyone before.

The problem is that the `elapsed time' reported by the receiver is merely the time difference between calling the functions rx_packet_recv() and rx_send_feedback(). This amounts on the average to 50 .. 100 usec.
With regard to RTT estimation, this is almost entirely useless.

Following is therefore a patch which tackles this problem with an alternative approach, I believe it is a bit better.

I have left in the clean-up operation of removing the last instance of skb_get_timestamp, hope that this is ok.

Due to the patch inter-dependencies, this patch is between the others, uploaded as

10e_CCID3-TIMESTAMP-FIX.diff

Thanks.