crt: tests: t_assert: do not set `stderr` to Unicode translation mode

By default, `assert` macro calls CRT function `_assert`; this function
does not work when `stderr` is set to Unicode translation mode.

This test was added in b2c3c92b542df57ed8bfcd798928692e94a35308 to
test mingw-w64 wrapper for `_assert`, which was added to make it work
in cases when `stderr` wsa set to Unicode translation mode.

With this change, t_assert becomes a simple test for `assert` macro.

Signed-off-by: Kirill Makurin <maiddaisuki@outlook.com>
Signed-off-by: LIU Hao <lh_mouse@126.com>

mingw-w64-crt/testcases/t_assert.c

diff --git a/mingw-w64-crt/testcases/t_assert.c b/mingw-w64-crt/testcases/t_assert.c
index 3c3da94..f3cec22 100644
--- a/mingw-w64-crt/testcases/t_assert.c
+++ b/mingw-w64-crt/testcases/t_assert.c
@@ -53,9 +53,6 @@
         return 0;
     }
 
-    /* change stderr to translated UNICODE mode */
-    _setmode(fileno(stderr), _O_U8TEXT);
-
     /* call assert, it prints to stderr, parent process will check that our stderr is not empty */
     assert(0);