improve fprintf related error handling

internal/debug/debug.go

@@ -120,7 +120,7 @@ func goroutineNum() int {
 	runtime.Stack(b, false)
 	var num int
 
-	fmt.Sscanf(string(b), "goroutine %d ", &num)
+	_, _ = fmt.Sscanf(string(b), "goroutine %d ", &num)
 	return num
 }
 

internal/debug/round_tripper.go

@@ -42,7 +42,7 @@ func (rd *eofDetectReader) Close() error {
 			msg += fmt.Sprintf(", body: %q", buf)
 		}
 
-		fmt.Fprintln(os.Stderr, msg)
+		_, _ = fmt.Fprintln(os.Stderr, msg)
 		Log("%s: %+v", msg, errors.New("Close()"))
 	}
 	return rd.rd.Close()