Remove unnecessary code.

Function will jump to error handler when ref buffer is corrupted.
So "xd->corrupted |= ref_buffer->buf->corrupted;" is useless.

Change-Id: I35353a0637ad0dbb682454e040ef69fa68280bfa

vp9/decoder/vp9_decodeframe.c

diff --git a/vp9/decoder/vp9_decodeframe.c b/vp9/decoder/vp9_decodeframe.c
index c54611f..1a9c4c2 100644
--- a/vp9/decoder/vp9_decodeframe.c
+++ b/vp9/decoder/vp9_decodeframe.c
@@ -397,7 +397,6 @@
                        "Block reference is corrupt");
   vp9_setup_pre_planes(xd, idx, ref_buffer->buf, mi_row, mi_col,
                        &ref_buffer->sf);
-  xd->corrupted |= ref_buffer->buf->corrupted;
 }
 
 static void decode_block(VP9_COMMON *const cm, MACROBLOCKD *const xd,