advapi32/tests: Skip not available functions.

dlls/advapi32/tests/security.c

@@ -910,8 +910,17 @@ static void test_AccessCheck(void)
     /* test INHERIT_ONLY_ACE */
     ret = InitializeAcl(Acl, 256, ACL_REVISION);
     ok(ret, "InitializeAcl failed with error %d\n", GetLastError());
+
+    /* NT doesn't have AddAccessAllowedAceEx. Skipping this call/test doesn't influence
+     * the next ones.
+     */
+    if (pAddAccessAllowedAceEx)
+    {
         ret = pAddAccessAllowedAceEx(Acl, ACL_REVISION, INHERIT_ONLY_ACE, KEY_READ, EveryoneSid);
         ok(ret, "AddAccessAllowedAceEx failed with error %d\n", GetLastError());
+    }
+    else
+        skip("AddAccessAllowedAceEx is not available\n");
 
     ret = AccessCheck(SecurityDescriptor, Token, KEY_READ, &Mapping,
                       PrivSet, &PrivSetLen, &Access, &AccessStatus);