Drop useless XCB_DESTROY_NOTIFY from big event switch statement

Summary: It just returned false, but that's also the default handling.

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D7938

events.cpp

@@ -315,9 +315,6 @@ bool Workspace::workspaceEvent(xcb_generic_event_t *e)
         //window manager who does the reparenting.
         return true;
     }
-    case XCB_DESTROY_NOTIFY: {
-        return false;
-    }
     case XCB_MAP_REQUEST: {
         updateXTime();