autotest: allow run without $PATH setup

Tools/autotest/run_in_terminal_window.sh

@@ -21,6 +21,6 @@ else
   echo "Window access not found, logging to $filename"
   cmd="$1"
   shift
-  ( run_cmd.sh $cmd $* &>$filename < /dev/null ) &
+  ( $AUTOTEST/run_cmd.sh $cmd $* &>$filename < /dev/null ) &
 fi
 exit 0

Tools/autotest/sim_vehicle.sh

@@ -285,6 +285,8 @@ pushd $autotest/../../$VEHICLE || {
     usage
     exit 1
 }
+AUTOTEST=$autotest
+export AUTOTEST
 VEHICLEDIR=$(pwd)
 
 if [ $NO_REBUILD == 0 ]; then