Reusing get_frame_new_buffer() function.

Change-Id: Iac5c5aeaef62a4095a60d91285d2c7ad717db0fb
diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index 6894f55..8c27670 100644
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -560,7 +560,6 @@
   VP9_COMMON *const cm = &cpi->common;
   MACROBLOCKD *const xd = &x->e_mbd;
   MB_MODE_INFO *mbmi;
-  const int dst_fb_idx = cm->new_fb_idx;
   const int idx_str = xd->mode_info_stride * mi_row + mi_col;
   const int mi_width = num_8x8_blocks_wide_lookup[bsize];
   const int mi_height = num_8x8_blocks_high_lookup[bsize];
@@ -587,7 +586,7 @@
   mbmi = &xd->mi_8x8[0]->mbmi;
 
   // Set up destination pointers
-  setup_dst_planes(xd, &cm->yv12_fb[dst_fb_idx], mi_row, mi_col);
+  setup_dst_planes(xd, get_frame_new_buffer(cm), mi_row, mi_col);
 
   // Set up limit values for MV components
   // mv beyond the range do not produce new/different prediction block