platform.c: Do not depend Windows build on HAVE_CHDIR

This broke in the CMake build since previously we
just always set HAVE_CHDIR to 1 in the MSVC build.
But actually the code should just not check HAVE_CHDIR
on Windows.

Github: fixes OpenVPN/openvpn#448

Change-Id: I0c78ce452135fe2c80275da449215ba926471018
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Lev Stipakov <lstipakov@gmail.com>
Message-Id: <20231111081808.30967-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27362.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 012ea92)

src/openvpn/platform.c

@@ -392,19 +392,19 @@ platform_mlockall(bool print_msg)
 int
 platform_chdir(const char *dir)
 {
-#ifdef HAVE_CHDIR
 #ifdef _WIN32
     int res;
     struct gc_arena gc = gc_new();
     res = _wchdir(wide_string(dir, &gc));
     gc_free(&gc);
     return res;
 #else  /* ifdef _WIN32 */
+#ifdef HAVE_CHDIR
     return chdir(dir);
-#endif
 #else  /* ifdef HAVE_CHDIR */
     return -1;
 #endif
+#endif
 }
 
 /*