gotest: make _testmain.go conform to gofmt rules

Otherwise, running "gofmt -d ." after "gotest" gives some
spurious changes.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5504101

src/cmd/gotest/gotest.go

@@ -401,7 +401,7 @@ func writeTestmainGo() {
 	fmt.Fprintln(b) // for gofmt
 
 	// Tests.
-	fmt.Fprintln(b, "var tests = []testing.InternalTest{")
+	fmt.Fprintln(b, "var tests = []testing.InternalTest{\n")
 	for _, f := range files {
 		for _, t := range f.tests {
 			fmt.Fprintf(b, "\t{\"%s.%s\", %s.%s},\n", f.pkg, t, renamedPackage(f.pkg), t)
@@ -411,7 +411,7 @@ func writeTestmainGo() {
 	fmt.Fprintln(b)
 
 	// Benchmarks.
-	fmt.Fprintf(b, "var benchmarks = []testing.InternalBenchmark{")
+	fmt.Fprintf(b, "var benchmarks = []testing.InternalBenchmark{\n")
 	for _, f := range files {
 		for _, bm := range f.benchmarks {
 			fmt.Fprintf(b, "\t{\"%s.%s\", %s.%s},\n", f.pkg, bm, renamedPackage(f.pkg), bm)