flatland: remove an unneeded #include

Change-Id: I50831d4efd543664ff7df7aaef35d842aebf1bd6
diff --git a/cmds/flatland/GLHelper.cpp b/cmds/flatland/GLHelper.cpp
index 31b1e06..3647897 100644
--- a/cmds/flatland/GLHelper.cpp
+++ b/cmds/flatland/GLHelper.cpp
@@ -14,8 +14,6 @@
  * limitations under the License.
  */
 
-#include <ui/Fence.h>
-
 #include <ui/DisplayInfo.h>
 #include <gui/SurfaceComposerClient.h>