clean up format strings

These were causing `go test` to fail.

Bug: None
Test: manual
Change-Id: Ia24ddae169b680befc25c6fd63350ed34979bb34
diff --git a/ui/build/soong.go b/ui/build/soong.go
index 0963f76..82e5c96 100644
--- a/ui/build/soong.go
+++ b/ui/build/soong.go
@@ -501,7 +501,7 @@
 	tf := filepath.Join(outDir, ".top")
 	defer func() {
 		if err := os.WriteFile(tf, []byte(cwd), 0644); err != nil {
-			fmt.Fprintf(os.Stderr, fmt.Sprintf("Unable to log CWD: %v", err))
+			fmt.Fprintf(os.Stderr, "Unable to log CWD: %v", err)
 		}
 	}()
 
diff --git a/ui/build/test_build.go b/ui/build/test_build.go
index ba53119..7a2fd16 100644
--- a/ui/build/test_build.go
+++ b/ui/build/test_build.go
@@ -151,7 +151,7 @@
 
 		ts.FinishAction(status.ActionResult{
 			Action: action,
-			Error:  fmt.Errorf(title),
+			Error:  fmt.Errorf("%s", title),
 			Output: sb.String(),
 		})
 		ctx.Fatal("stopping")