[newlib-cygwin] Cygwin: cwdstuff::get: clean up debug_printf output

[Ken Brown]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=c1f177d6a9e0b86f9ad22c49891fd2d60433e472

commit c1f177d6a9e0b86f9ad22c49891fd2d60433e472
Author: Ken Brown <kbrown@cornell.edu>
Date:   Sun Aug 23 18:41:18 2020 -0400

    Cygwin: cwdstuff::get: clean up debug_printf output
    
    Set errno = 0 at the beginning so that the debug_printf call at the
    end doesn't report a nonzero errno left over from some other function
    call.

Diff:
---
 winsup/cygwin/path.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index f3b9913bd..95faf8ca7 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -5022,6 +5022,8 @@ char *
 cwdstuff::get (char *buf, int need_posix, int with_chroot, unsigned ulen)
 {
   tmp_pathbuf tp;
+
+  errno = 0;
   if (ulen)
     /* nothing */;
   else if (buf == NULL)