overlord: change simple-logcat mode number

Change due to protocol change in Overlord.

BUG=chromium:443972
TEST=none

Change-Id: Ic722bbf6c44ccabe83a54d3063e7b467918ed400
Reviewed-on: https://chromium-review.googlesource.com/254032
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Queue: Wei-Ning Huang <wnhuang@chromium.org>
Tested-by: Wei-Ning Huang <wnhuang@chromium.org>
diff --git a/ping_shopfloor.sh b/ping_shopfloor.sh
index a339100..4acd34a 100644
--- a/ping_shopfloor.sh
+++ b/ping_shopfloor.sh
@@ -175,7 +175,7 @@
 
   local header_tty="$(mktemp)" header_log="$(mktemp)"
   local header='{"name":"register",
-                 "params":{"cid":"%s","mid":"%s","format":%s,"mode":3}}\r\n'
+                 "params":{"cid":"%s","mid":"%s","format":%s,"mode":4}}\r\n'
   printf "${header}" "Console" "${machine_id}" "1" >"${header_tty}"
   printf "${header}" "DebugLog" "${machine_id}" "0" >"${header_log}"