remove duplicate nil check separate var

call.go

@@ -164,11 +164,7 @@ func Invoke(ctx context.Context, method string, args, reply interface{}, cc *Cli
 			return toRPCErr(err)
 		}
 		if EnableTracing {
-			p := &payload{
-				sent: true,
-				msg:  args,
-			}
-			c.traceInfo.tr.LazyLog(p, true)
+			c.traceInfo.tr.LazyLog(&payload{sent: true, msg: args}, true)
 		}
 		stream, err = sendRequest(ctx, cc.dopts.codec, callHdr, t, args, topts)
 		if err != nil {
@@ -187,11 +183,7 @@ func Invoke(ctx context.Context, method string, args, reply interface{}, cc *Cli
 			continue
 		}
 		if EnableTracing {
-			p := &payload{
-				sent: false,
-				msg:  reply,
-			}
-			c.traceInfo.tr.LazyLog(p, true)
+			c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
 		}
 		t.CloseStream(stream, lastErr)
 		if lastErr != nil {

stream.go

@@ -166,11 +166,7 @@ func (cs *clientStream) SendMsg(m interface{}) (err error) {
 	if cs.tracing {
 		cs.mu.Lock()
 		if cs.traceInfo.tr != nil {
-			p := &payload{
-				sent: true,
-				msg:  m,
-			}
-			cs.traceInfo.tr.LazyLog(p, true)
+			cs.traceInfo.tr.LazyLog(&payload{sent: true, msg: m}, true)
 		}
 		cs.mu.Unlock()
 	}
@@ -202,13 +198,7 @@ func (cs *clientStream) RecvMsg(m interface{}) (err error) {
 		if cs.tracing {
 			cs.mu.Lock()
 			if cs.traceInfo.tr != nil {
-				if cs.traceInfo.tr != nil {
-					p := &payload{
-						sent: false,
-						msg:  m,
-					}
-					cs.traceInfo.tr.LazyLog(p, true)
-				}
+				cs.traceInfo.tr.LazyLog(&payload{sent: false, msg: m}, true)
 			}
 			cs.mu.Unlock()
 		}

trace.go

@@ -93,7 +93,7 @@ func (f *firstLine) String() string {
 
 // payload represents an RPC request or response payload.
 type payload struct {
-	sent bool        // whether this is a request or response
+	sent bool        // whether this is an outgoing payload
 	msg  interface{} // e.g. a proto.Message
 	// TODO(dsymonds): add stringifying info to codec, and limit how much we hold here?
 }