mshtml: Add failure detection to set_downloading_proc.

[Gerald Pfeifer]

Jacek was so kind to provide feedback in response to my patch at
http://www.winehq.org/pipermail/wine-patches/2011-July/104761.html
alas I lost his e-mail, but I hope I got the gist of his feedback.

(The nested if also could be && for the time being.)

Gerald

---
 dlls/mshtml/persist.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/dlls/mshtml/persist.c b/dlls/mshtml/persist.c
index b73476b..845bfe8 100644
--- a/dlls/mshtml/persist.c
+++ b/dlls/mshtml/persist.c
@@ -179,9 +179,11 @@ static void set_downloading_proc(task_t *_task)
         IDropTarget *drop_target = NULL;
 
         hres = IDocHostUIHandler_GetDropTarget(doc->hostui, NULL /* FIXME */, &drop_target);
-        if(drop_target) {
-            FIXME("Use IDropTarget\n");
-            IDropTarget_Release(drop_target);
+        if(SUCCEEDED(hres)) {
+            if(drop_target) {
+                FIXME("Use IDropTarget\n");
+                IDropTarget_Release(drop_target);
+            }
         }
     }
 }
-- 
1.7.6