advapi32/tests: Add some extra info to an ok() call.
diff --git a/dlls/advapi32/tests/eventlog.c b/dlls/advapi32/tests/eventlog.c
index ba9a897..0186f2b 100644
--- a/dlls/advapi32/tests/eventlog.c
+++ b/dlls/advapi32/tests/eventlog.c
@@ -1000,7 +1000,8 @@
         }
         lstrcpyA(p, eventlogname);
 
-        ok(!memcmp(sources, sources_verify, size), "Expected a correct 'Sources' value\n");
+        ok(!memcmp(sources, sources_verify, size),
+           "Expected a correct 'Sources' value (size : %d)\n", size);
     }
 
     RegCloseKey(eventkey);