internal/frontend: add missing arg to log.Errorf

Change-Id: I7dda2273facbf165df4fca53ff70981ddeb41e0e
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/350569
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jamal Carvalho <jamal@golang.org>
diff --git a/internal/frontend/404.go b/internal/frontend/404.go
index 3c57ce5..18950b6 100644
--- a/internal/frontend/404.go
+++ b/internal/frontend/404.go
@@ -110,7 +110,8 @@
 		//
 		// Return the fetch page so the user can try requesting again, and log
 		// an error.
-		log.Errorf(ctx, "version_map reports that %s@%s has status=%d, but this was not found before reaching servePathNotFoundPage", fullPath, requestedVersion)
+		log.Errorf(ctx, "version_map reports that %s@%s has status=%d, but this was not found before reaching servePathNotFoundPage",
+			fullPath, requestedVersion, fr.status)
 		return pathNotFoundError(ctx, fullPath, requestedVersion)
 	case http.StatusFound, derrors.ToStatus(derrors.AlternativeModule):
 		if fr.goModPath == fullPath {