ping_test: add argument to specify packet size

We find that using a bigger packet size seems to be able to catch some
hardware issue of RJ45 port.  We add 'packet_size' argument to specify
the ping packet size (the '-s' option).

BUG=None
TEST=manual

Change-Id: I2c871cf35c9254ab7eba255570f393282e1b9f4c
Reviewed-on: https://chromium-review.googlesource.com/373421
Commit-Ready: Wei-Han Chen <stimim@chromium.org>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Shun-Hsing Ou <shunhsingou@chromium.org>
1 file changed