use consistent alias for interal/test package

cmd/restic/cmd_restore_integration_test.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io"
-	mrand "math/rand"
+	"math/rand"
 	"os"
 	"path/filepath"
 	"syscall"
@@ -116,7 +116,7 @@ func TestRestore(t *testing.T) {
 	for i := 0; i < 10; i++ {
 		p := filepath.Join(env.testdata, fmt.Sprintf("foo/bar/testfile%v", i))
 		rtest.OK(t, os.MkdirAll(filepath.Dir(p), 0755))
-		rtest.OK(t, appendRandomData(p, uint(mrand.Intn(2<<21))))
+		rtest.OK(t, appendRandomData(p, uint(rand.Intn(2<<21))))
 	}
 
 	opts := BackupOptions{}