Fix format string issues

Fix issues caught by go vet.

Test: m checkbuild
Change-Id: Ib8d740457c15432dabe1575a6707726ddaf93084
diff --git a/ui/logger/logger.go b/ui/logger/logger.go
index 15c413d..c763e50 100644
--- a/ui/logger/logger.go
+++ b/ui/logger/logger.go
@@ -85,7 +85,7 @@
 	}
 
 	if err := os.Rename(from, newName); err != nil {
-		return fmt.Errorf("Failed to rotate", from, "to", newName, ".", err)
+		return fmt.Errorf("Failed to rotate %s to %s. %s", from, newName, err)
 	}
 	return nil
 }