Remove un-necessary memory initialization

The intra prediction needs one line above at the top edge.
diff --git a/vp8/common/setupintrarecon.c b/vp8/common/setupintrarecon.c
index dcaafe6..38bfae8 100644
--- a/vp8/common/setupintrarecon.c
+++ b/vp8/common/setupintrarecon.c
@@ -16,21 +16,15 @@
     int i;
 
     // set up frame new frame for intra coded blocks
-    vpx_memset(ybf->y_buffer - 1 - 2 * ybf->y_stride, 127, ybf->y_width + 5);
     vpx_memset(ybf->y_buffer - 1 - ybf->y_stride, 127, ybf->y_width + 5);
-
     for (i = 0; i < ybf->y_height; i++)
         ybf->y_buffer[ybf->y_stride *i - 1] = (unsigned char) 129;
 
-    vpx_memset(ybf->u_buffer - 1 - 2 * ybf->uv_stride, 127, ybf->uv_width + 5);
     vpx_memset(ybf->u_buffer - 1 - ybf->uv_stride, 127, ybf->uv_width + 5);
-
     for (i = 0; i < ybf->uv_height; i++)
         ybf->u_buffer[ybf->uv_stride *i - 1] = (unsigned char) 129;
 
-    vpx_memset(ybf->v_buffer - 1 - 2 * ybf->uv_stride, 127, ybf->uv_width + 5);
     vpx_memset(ybf->v_buffer - 1 - ybf->uv_stride, 127, ybf->uv_width + 5);
-
     for (i = 0; i < ybf->uv_height; i++)
         ybf->v_buffer[ybf->uv_stride *i - 1] = (unsigned char) 129;