Use comma not pipe in switch-case

brings down time to complete by 40%

Bug: NA
Test: m queryview and m soong_docs
Change-Id: I3681e2f5015fc1f5cabaf0462d4d52a4fe9db56c
diff --git a/cmd/soong_build/main.go b/cmd/soong_build/main.go
index 744a10c..fe928ad 100644
--- a/cmd/soong_build/main.go
+++ b/cmd/soong_build/main.go
@@ -277,7 +277,7 @@
 	switch ctx.Config().BuildMode {
 	case android.GenerateModuleGraph:
 		stopBefore = bootstrap.StopBeforeWriteNinja
-	case android.GenerateQueryView | android.GenerateDocFile:
+	case android.GenerateQueryView, android.GenerateDocFile:
 		stopBefore = bootstrap.StopBeforePrepareBuildActions
 	default:
 		stopBefore = bootstrap.DoEverything