multiChoice: use stdout.Fd instead of hardcoded zero

Author: chessman

ishell.go

@@ -478,7 +478,8 @@ func (s *Shell) multiChoice(options []string, text string, init []int, multiResu
 		return nil
 	}
 
-	_, maxRows, err := readline.GetSize(0)
+	stdoutFd := int(os.Stdout.Fd())
+	_, maxRows, err := readline.GetSize(stdoutFd)
 	if err != nil {
 		return nil
 	}
@@ -559,7 +560,7 @@ func (s *Shell) multiChoice(options []string, text string, init []int, multiResu
 			case <-refresh:
 				update()
 			case <-t.C:
-				_, rows, _ := readline.GetSize(0)
+				_, rows, _ := readline.GetSize(stdoutFd)
 				if maxRows != rows {
 					maxRows = rows
 					update()