Remove single-entry var blocks (#1589)

benchmark/server/main.go

@@ -30,9 +30,7 @@ import (
 	"google.golang.org/grpc/grpclog"
 )
 
-var (
-	duration = flag.Int("duration", math.MaxInt32, "The duration in seconds to run the benchmark server")
-)
+var duration = flag.Int("duration", math.MaxInt32, "The duration in seconds to run the benchmark server")
 
 func main() {
 	flag.Parse()

benchmark/worker/benchmark_client.go

@@ -37,9 +37,7 @@ import (
 	"google.golang.org/grpc/testdata"
 )
 
-var (
-	caFile = flag.String("ca_file", "", "The file containing the CA root cert file")
-)
+var caFile = flag.String("ca_file", "", "The file containing the CA root cert file")
 
 type lockingHistogram struct {
 	mu        sync.Mutex