trex: Enforce 10 iterations for RFC2544 tput

trex: Enforce 10 iterations for RFC2544 tput

This patch enforces 10 iterations during search
for besti RFC2544 Throughput with 0% packet loss. Unless
0% packet loss is detected during first iteration
with initial frame rate.

JIRA: VSPERF-530

Change-Id: I99e49e9dbf4e1424253d0cfec804819516c00df8
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Christian Trautman <ctrautma@redhat.com>
Reviewed-by: Sridhar Rao <sridhar.rao@spirent.com>
Reviewed-by: Trevor Cooper <trevor.cooper@intel.com>
Reviewed-by: Martin Goldammer <martin.goldammer6@gmail.com>