[glibc] libio: use _IO_have_wbackup for wide streams

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=4e22f9505703fd88a249d37fb6c8320bd1bbc815

commit 4e22f9505703fd88a249d37fb6c8320bd1bbc815
Author: Andreas Schwab <[email protected]>
Date:   Tue Mar 31 10:54:01 2026 +0200

    libio: use _IO_have_wbackup for wide streams
    
    Fix two wrong uses of _IO_have_backup on a wide stream.

Diff:
---
 libio/wgenops.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libio/wgenops.c b/libio/wgenops.c
index 5f36bc49a1..c2a8541b6d 100644
--- a/libio/wgenops.c
+++ b/libio/wgenops.c
@@ -270,7 +270,7 @@ __wunderflow (FILE *fp)
       if (save_for_wbackup (fp, fp->_wide_data->_IO_read_end))
 	return WEOF;
     }
-  else if (_IO_have_backup (fp))
+  else if (_IO_have_wbackup (fp))
     _IO_free_wbackup_area (fp);
   return _IO_UNDERFLOW (fp);
 }
@@ -603,6 +603,6 @@ _IO_unsave_wmarkers (FILE *fp)
       fp->_markers = NULL;
     }
 
-  if (_IO_have_backup (fp))
+  if (_IO_have_wbackup (fp))
     _IO_free_wbackup_area (fp);
 }