Fix 4:2:0 assumptions in debug plane output

Fixes some debugging code to be able to write out frames with
chroma other than 4:2:0.

Change-Id: I5ee3d29e584db1f52d2de344db249e927eff10b7
diff --git a/vp9/encoder/vp9_onyx_if.c b/vp9/encoder/vp9_onyx_if.c
index 58f8fdb..e55f555 100644
--- a/vp9/encoder/vp9_onyx_if.c
+++ b/vp9/encoder/vp9_onyx_if.c
@@ -1941,8 +1941,8 @@
   pkt.data.psnr.samples[0] = width * height;
   pkt.data.psnr.samples[1] = width * height;
 
-  width = (width + 1) / 2;
-  height = (height + 1) / 2;
+  width = orig->uv_width;
+  height = orig->uv_height;
 
   sse = calc_plane_error(orig->u_buffer, orig->uv_stride,
                          recon->u_buffer, recon->uv_stride,
@@ -2096,7 +2096,7 @@
   } while (--h);
 
   src = s->u_buffer;
-  h = (cm->height + 1) / 2;
+  h = s->uv_height;
 
   do {
     fwrite(src, s->uv_width, 1,  yuv_rec_file);
@@ -2104,7 +2104,7 @@
   } while (--h);
 
   src = s->v_buffer;
-  h = (cm->height + 1) / 2;
+  h = s->uv_height;
 
   do {
     fwrite(src, s->uv_width, 1, yuv_rec_file);