Fixed typo.

diff --git a/dlls/msvcrt/file.c b/dlls/msvcrt/file.c
index cc86341..f26cae0 100644
--- a/dlls/msvcrt/file.c
+++ b/dlls/msvcrt/file.c
@@ -1439,7 +1439,7 @@
   if ((mode & _O_TEXT) == _O_TEXT)
       MSVCRT_fdesc[fd].xflag |= WX_TEXT;
   else
-      MSVCRT_fdesc[fd].xflag &= WX_TEXT;
+      MSVCRT_fdesc[fd].xflag &= ~WX_TEXT;
   return ret;
 }