Expect :pthread_detach to fail with EINVAL instead of ESRCH on FreeBSD

PR: 191906
In collaboration with: pho

contrib/netbsd-tests/lib/libpthread/t_detach.c

@@ -75,6 +75,10 @@ ATF_TC_BODY(pthread_detach, tc)
 	rv = pthread_join(t, NULL);
 	ATF_REQUIRE(rv == EINVAL);
 
+#if defined(__FreeBSD__)
+	atf_tc_expect_fail("PR # 191906: fails with EINVAL, not ESRCH");
+#endif
+
 	/*
 	 * As usual, ESRCH should follow if
 	 * we try to detach an invalid thread.