test: fix the data race in restore test (pingcap#57762)

close pingcap#57760

br/pkg/restore/restorer_test.go

@@ -3,6 +3,7 @@ package restore_test
 
 import (
 	"context"
+	"sync"
 	"testing"
 
 	"github.com/pingcap/errors"
@@ -65,8 +66,11 @@ func TestSimpleRestorerImportAndProgress(t *testing.T) {
 		{SSTFiles: files},
 	}
 	progressCount = int64(0)
+	var mu sync.Mutex
 	err = restorer.GoRestore(func(progress int64) {
+		mu.Lock()
 		progressCount += progress
+		mu.Unlock()
 	}, batchFileSet)
 	require.NoError(t, err)
 	err = restorer.WaitUntilFinish()
@@ -145,7 +149,12 @@ func TestMultiTablesRestorerRestoreSuccess(t *testing.T) {
 	var progress int64
 	fileSets := createSampleBatchFileSets()
 
-	restorer.GoRestore(func(p int64) { progress += p }, fileSets)
+	var mu sync.Mutex
+	restorer.GoRestore(func(p int64) {
+		mu.Lock()
+		progress += p
+		mu.Unlock()
+	}, fileSets)
 	err := restorer.WaitUntilFinish()
 	require.NoError(t, err)