Find correct border under pointer

Previously we would find the first border and then break. Now we find
the border with the highest layer, as the code intended.

Fixes CID 1039952

src/bin/e_border.c

@@ -9948,10 +9948,7 @@ _e_border_under_pointer_helper(E_Desk *desk, E_Border *exclude, int x, int y)
         /* If the layer is higher, the position of the window is higher
          * (always on top vs always below) */
         if (!bd || (cbd->layer > bd->layer))
-          {
-             bd = cbd;
-             break;
-          }
+          bd = cbd;
      }
    return bd;
 }