cros_run_bvt: Add clarifying information for expected servo_type

BUG=None
TEST=Verified displayed message when incorrect servo_type passed in

Change-Id: I295d71bf715daa995bfcfdb8b21d4624f7e4c093
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/4769512
Commit-Queue: Kevin Shelton <kmshelton@chromium.org>
Auto-Submit: Bob Moragues <moragues@chromium.org>
Tested-by: Bob Moragues <moragues@chromium.org>
Reviewed-by: YH Lin <yueherngl@chromium.org>
Commit-Queue: Bob Moragues <moragues@chromium.org>
Reviewed-by: Kevin Shelton <kmshelton@chromium.org>
1 file changed