This patch adds retry option in testpmd to prevent most packet losses.
It can be enabled by "set fwd <mode> retry". All modes except rxonly
support this option.
Adding retry mechanism expands test case coverage to support scenarios
where packet loss affects test results.
Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>