cmd: avoid printing redundant newlines

For golang/go#49350

Change-Id: Ic566112ff8a8707998b461d2b99fca852f2972f8
Reviewed-on: https://go-review.googlesource.com/c/tools/+/361716
Run-TryBot: Zvonimir Pavlinovic <zpavlinovic@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Zvonimir Pavlinovic <zpavlinovic@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

cmd/callgraph/main.go

@@ -166,7 +166,7 @@ var stdout io.Writer = os.Stdout
 
 func doCallgraph(dir, gopath, algo, format string, tests bool, args []string) error {
 	if len(args) == 0 {
-		fmt.Fprintln(os.Stderr, Usage)
+		fmt.Fprint(os.Stderr, Usage)
 		return nil
 	}
 

cmd/cover/cover.go

@@ -42,8 +42,8 @@ Finally, to generate modified source code with coverage annotations
 `
 
 func usage() {
-	fmt.Fprintln(os.Stderr, usageMessage)
-	fmt.Fprintln(os.Stderr, "Flags:")
+	fmt.Fprint(os.Stderr, usageMessage)
+	fmt.Fprintln(os.Stderr, "\nFlags:")
 	flag.PrintDefaults()
 	fmt.Fprintln(os.Stderr, "\n  Only one of -html, -func, or -mode may be set.")
 	os.Exit(2)

cmd/eg/eg.go

@@ -59,7 +59,8 @@ func doMain() error {
 	args := flag.Args()
 
 	if *helpFlag {
-		fmt.Fprint(os.Stderr, eg.Help)
+		help := eg.Help // hide %s from vet
+		fmt.Fprint(os.Stderr, help)
 		os.Exit(2)
 	}
 

cmd/gomvpkg/main.go

@@ -83,7 +83,7 @@ func main() {
 	}
 
 	if *helpFlag || *fromFlag == "" || *toFlag == "" {
-		fmt.Println(Usage)
+		fmt.Print(Usage)
 		return
 	}
 

cmd/gorename/main.go

@@ -46,7 +46,7 @@ func main() {
 	}
 
 	if *helpFlag || (*offsetFlag == "" && *fromFlag == "" && *toFlag == "") {
-		fmt.Println(rename.Usage)
+		fmt.Print(rename.Usage)
 		return
 	}
 

cmd/gotype/gotype.go

@@ -167,7 +167,8 @@ files to include for such packages.
 `
 
 func usage() {
-	fmt.Fprintln(os.Stderr, usageString)
+	fmt.Fprint(os.Stderr, usageString)
+	fmt.Fprintln(os.Stderr)
 	flag.PrintDefaults()
 	os.Exit(2)
 }

cmd/guru/main.go

@@ -105,8 +105,8 @@ Example: describe syntax at offset 530 in this file (an import spec):
 `
 
 func printHelp() {
-	fmt.Fprintln(os.Stderr, helpMessage)
-	fmt.Fprintln(os.Stderr, "Flags:")
+	fmt.Fprint(os.Stderr, helpMessage)
+	fmt.Fprintln(os.Stderr, "\nFlags:")
 	flag.PrintDefaults()
 }