Sample the log traffic to work out its data rate so that we

have a better idea of predicting when it will get to the end
of the log. This way we can handle a change in log traffic in
the future. A test to keep an eye on log traffic is more of
a performance test than should be done elsewhere.
Merge of master-melb:xfs-cmds:31053a by kenmcd.

  Sample the log traffic to work out its data rate so that we
  have a better idea of predicting when it will get to the end
  of the log. This way we can handle a change in log traffic in
  the future.

016.out

@@ -11,6 +11,10 @@ Wrote 51200.00Kb (value 0xc6)
    *** mount
    *** fiddle
    *** unmount
+*** generate log traffic
+   *** mount
+   *** fiddle
+   *** unmount
 *** check for corruption
 *** generate log traffic
    *** mount