Fix govet issue

Change-Id: I67705c5c1240bea6a21b7d62fd26d296d49735d4
diff --git a/cmd/soong_glob/soong_glob.go b/cmd/soong_glob/soong_glob.go
index 6f56bb9..83b8154 100644
--- a/cmd/soong_glob/soong_glob.go
+++ b/cmd/soong_glob/soong_glob.go
@@ -61,7 +61,7 @@
 	flag.Parse()
 
 	if *out == "" {
-		fmt.Fprintln(os.Stderr, "error: -o is required\n")
+		fmt.Fprintf(os.Stderr, "error: -o is required\n")
 		usage()
 	}