Only check gen directory for golden tests am: d23ba31cd5

Original change: https://android-review.googlesource.com/c/platform/system/tools/aidl/+/1919080

Change-Id: Ib0a9d7a82ff292c660cb07285b6399dda878255a
diff --git a/tests/golden_test.sh b/tests/golden_test.sh
index b9b7f3a..018f670 100755
--- a/tests/golden_test.sh
+++ b/tests/golden_test.sh
@@ -70,7 +70,7 @@
       mkdir -p "$golden"
       cp -r "$built/gen" "$golden"
     else
-      diff -r "$built" "$golden" || e=1
+      diff -r "$built/gen" "$golden/gen" || e=1
     fi
   done