Fixed two issues pointed out in a PVS-Studio static code analyzer article (bug #5505).

code/ui/ui_shared.c

@@ -3831,7 +3831,8 @@ void Item_OwnerDraw_Paint(itemDef_t *item) {
 
 void Item_Paint(itemDef_t *item) {
   vec4_t red;
-  menuDef_t *parent = (menuDef_t*)item->parent;
+  menuDef_t *parent;
+
   red[0] = red[3] = 1;
   red[1] = red[2] = 0;
 
@@ -3839,6 +3840,8 @@ void Item_Paint(itemDef_t *item) {
     return;
   }
 
+  parent = (menuDef_t*)item->parent;
+
   if (item->window.flags & WINDOW_ORBITING) {
     if (DC->realTime > item->window.nextTime) {
       float rx, ry, a, c, s, w, h;