flock tests: Don't expect a failure on native Windows

[Bruno Haible]

On mingw and MSVC, the replacement code from lib/flock.c is working fine.
No test failure here.


2024-06-03  Bruno Haible  <br...@clisp.org>

        flock tests: Don't expect a failure on native Windows.
        * modules/flock-tests (Depends-on): Add test-xfail.
        (Makefile.am): Don't augment XFAIL_TESTS on native Windows.

diff --git a/modules/flock-tests b/modules/flock-tests
index c5cd8f05cd..27670e92aa 100644
--- a/modules/flock-tests
+++ b/modules/flock-tests
@@ -5,6 +5,7 @@ tests/macros.h
 
 Depends-on:
 unistd
+test-xfail
 
 configure.ac:
 
@@ -13,5 +14,7 @@ TESTS += test-flock
 check_PROGRAMS += test-flock
 
 if GL_COND_OBJ_FLOCK
+if !OS_IS_NATIVE_WINDOWS
 XFAIL_TESTS += test-flock
 endif
+endif