[newlib-cygwin] Cygwin: serial: Fix a copy-paste error in DTR setup

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=a263fe0b268580273c1adc4b1bad256147990222

commit a263fe0b268580273c1adc4b1bad256147990222
Author: Carlo Bramini <30959007+carlo-bramini@users.noreply.github.com>
Date:   Tue Nov 29 10:02:43 2022 +0100

    Cygwin: serial: Fix a copy-paste error in DTR setup
    
    In commit 2dab880c963ce0204c3513d664f610b587a3e6a6 I did a mistake when
    I copied the new fhandler_serial::switch_modem_lines() from my modified
    3.3.6 branch to the current master and I left a copy paste error. This
    patch fixes that error.
    
    Fixes: 2dab880c963c ("Cygwin: fix TIOCMBIS/TIOCMBIC not working when using usbser.sys")

Diff:
---
 winsup/cygwin/fhandler/serial.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/winsup/cygwin/fhandler/serial.cc b/winsup/cygwin/fhandler/serial.cc
index 58a8df677..e04f8f263 100644
--- a/winsup/cygwin/fhandler/serial.cc
+++ b/winsup/cygwin/fhandler/serial.cc
@@ -411,10 +411,10 @@ fhandler_serial::switch_modem_lines (int set, int clr)
         dcb.fRtsControl = RTS_CONTROL_DISABLE;
 
       if (set & TIOCM_DTR)
-        dcb.fRtsControl = DTR_CONTROL_ENABLE;
+        dcb.fDtrControl = DTR_CONTROL_ENABLE;
       else
       if (clr & TIOCM_DTR)
-        dcb.fRtsControl = DTR_CONTROL_DISABLE;
+        dcb.fDtrControl = DTR_CONTROL_DISABLE;
 
       if (!SetCommState(get_handle(), &dcb))
         {