-n broken in iperf 2.0.2

[lowekamp --at-- cs.wm.edu]

in iperf-2.0.2, -n doesn't work (should limit # of bytes sent, instead
causes it to run forever).  I can't find any mention of this in the
mailing list, so I'll report it.

cause:

mAmount is set to the # of bytes to send, then decremented.  The code
exits when it's < 0, but it's declared as an unsigned.

here's a simple patch assuming it's OK to sacrifice the sign bit:
line 157 of include/Settings.hpp is:
  max_size_t mAmount;             // -n or -t

should be:

  intmax_t mAmount;             // -n or -t

(possibly replace intmax_t with a more generic name added to
headers.h)

Bruce