UPSTREAM: tests: Update prefer_vht40 throughput estimation

Match the updated max_ht40_rate() estimation with VHT.

Signed-off-by: Jouni Malinen <j@w1.fi>
(cherry picked from commit 275509ee673c96e3546901013f02a7ab0c22691e)
Signed-off-by: Matthew Wang <matthewmwang@chromium.org>

BUG=chromium:1014866,chromium:1049782
TEST=`tast -verbose run -var=network.HostapHwsim.runArgs='-f ap_vht'
localhost:9222 network.HostapHwsim.full`

Change-Id: I6b9de59c2de29b8efb5e9eff5bfdfcd7b09f224e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/hostap/+/2128895
Reviewed-by: Brian Norris <briannorris@chromium.org>
Commit-Queue: Matthew Wang <matthewmwang@chromium.org>
Tested-by: Matthew Wang <matthewmwang@chromium.org>
1 file changed