advapi32/tests: Avoid crashing if ReadEventLogA fails.

[Paul Vriens]

Hi Alexandre,

+        if (ReadEventLogA(handle, EVENTLOG_SEQUENTIAL_READ | 
EVENTLOG_FORWARDS_READ,
+                          0, buf, sizeof(EVENTLOGRECORD), &read, &needed))
+        {

I don't think this is correct. The first call will always fail as the 
buffer is not big enough. This now introduces a test failure on Vista 
without a servicepack (what this piece of code was meant to check).

I guess a 'better' fix would have been to set needed to 0 in our 
implementation until ReadEventLog is fully implemented.

-- 
Cheers,

Paul.