motion_est_template: fix warning: "ASSERT_LEVEL" is not defined

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/motion_est_template.c

@@ -89,7 +89,7 @@ static int hpel_motion_search(MpegEncContext * s,
         const int b= score_map[(index+(1<<ME_MAP_SHIFT))&(ME_MAP_SIZE-1)]
                      + (mv_penalty[bx   - pred_x] + mv_penalty[by+2 - pred_y])*c->penalty_factor;
 
-#if ASSERT_LEVEL > 1
+#if defined(ASSERT_LEVEL) && ASSERT_LEVEL > 1
         unsigned key;
         unsigned map_generation= c->map_generation;
         key= ((my-1)<<ME_MAP_MV_BITS) + (mx) + map_generation;