oledb32: Avoid leaking propsets on error paths (Coverity).

dlls/oledb32/datainit.c

@@ -293,11 +293,10 @@ static HRESULT set_dbpropset(BSTR name, BSTR value, DBPROPSET **propset)
 {
     static const WCHAR datasourceW[] = {'D','a','t','a',' ','S','o','u','r','c','e',0};
 
-    *propset = CoTaskMemAlloc(sizeof(DBPROPSET));
-    (*propset)->rgProperties = CoTaskMemAlloc(sizeof(DBPROP));
-
     if (!strcmpW(datasourceW, name))
     {
+        *propset = CoTaskMemAlloc(sizeof(DBPROPSET));
+        (*propset)->rgProperties = CoTaskMemAlloc(sizeof(DBPROP));
         (*propset)->cProperties = 1;
         (*propset)->guidPropertySet = DBPROPSET_DBINIT;
         (*propset)->rgProperties[0].dwPropertyID = DBPROP_INIT_DATASOURCE;
@@ -310,6 +309,7 @@ static HRESULT set_dbpropset(BSTR name, BSTR value, DBPROPSET **propset)
     }
     else
     {
+        *propset = NULL;
         FIXME("unsupported property %s\n", debugstr_w(name));
         return E_FAIL;
     }