Simplify a list-removal operation in QTestLog's handleIgnoredMessage()

When list->next is nullptr, setting ignoreResultList to list->next is
the same as setting it to nullptr.

Change-Id: If328ce31db4344cf0136b7a827be871eb89e35b5
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

src/testlib/qtestlog.cpp

@@ -164,10 +164,8 @@ namespace QTest {
                 // remove the item from the list
                 if (last)
                     last->next = list->next;
-                else if (list->next)
-                    ignoreResultList = list->next;
                 else
-                    ignoreResultList = nullptr;
+                    ignoreResultList = list->next;
 
                 delete list;
                 return true;