fix goroutine leak in restoreData

tests/import_goroutine_leak/run.sh

@@ -55,23 +55,22 @@ function run() {
         exit 2
     fi
 
-    echo "" > $WORK_DIR/worker1/log/stdout.log
     echo "dm-workers paninc again, workers of import unit don't exit"
     # check workers of import unit exit
     inject_points=("github.com/pingcap/dm/loader/dontWaitWorkerExit=return(1)"
-                   "github.com/pingcap/dm/loader/LoadDataSlowDown=sleep(5000)"
+                   "github.com/pingcap/dm/loader/LoadDataSlowDown=sleep(1000)"
                    "github.com/pingcap/dm/loader/executeSQLError=return(1)"
                    )
     export GO_FAILPOINTS="$(join_string \; ${inject_points[@]})"
     run_dm_worker $WORK_DIR/worker1 $WORKER1_PORT $cur/conf/dm-worker1.toml
     run_dm_worker $WORK_DIR/worker2 $WORKER2_PORT $cur/conf/dm-worker2.toml
-
+    sleep 2s
     check_port_offline $WORKER1_PORT 20
     check_port_offline $WORKER2_PORT 20
 
     # dm-worker1 panics
     err_cnt=`grep "panic" $WORK_DIR/worker1/log/stdout.log | wc -l`
-    if [ $err_cnt -ne 1 ]; then
+    if [ $err_cnt -ne 2 ]; then
         echo "dm-worker1 doesn't panic again, panic count ${err_cnt}"
         exit 2
     fi