Code clean up.

No need to check pbi->common.frame_to_show again.

Change-Id: I572ea4afd0d8b6000c0bb7575b7023d75cad5a4e
diff --git a/vp9/decoder/vp9_decoder.c b/vp9/decoder/vp9_decoder.c
index c954a5d..b3e3f9c 100644
--- a/vp9/decoder/vp9_decoder.c
+++ b/vp9/decoder/vp9_decoder.c
@@ -422,19 +422,12 @@
 #if CONFIG_VP9_POSTPROC
   ret = vp9_post_proc_frame(&pbi->common, sd, flags);
 #else
-
-  if (pbi->common.frame_to_show) {
     *sd = *pbi->common.frame_to_show;
     sd->y_width = pbi->common.width;
     sd->y_height = pbi->common.height;
     sd->uv_width = sd->y_width >> pbi->common.subsampling_x;
     sd->uv_height = sd->y_height >> pbi->common.subsampling_y;
-
     ret = 0;
-  } else {
-    ret = -1;
-  }
-
 #endif /*!CONFIG_POSTPROC*/
   vp9_clear_system_state();
   return ret;