Rx: properly compute dataPacketsReSent statistic

Rx: properly compute dataPacketsReSent statistic

The global dataPacketsReSent statistic should be the sum of all
peer->reSends and dataPacketsSent should not include the count of
resent packets.  Prior to this patchset, dataPacketsSent included
the resent packets and dataPacketsReSent was computed as the number
of requests for Ack instead of the number of packets resent.

Change-Id: I969003f7ec1805d09c14ac342453f86fdb5df99a
Reviewed-on: http://gerrit.openafs.org/2776
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>