Fix use of wrong context in i8x8 coefficient cost calculation.

Change-Id: Ica58d0c7d8addb5ddd5d6e1fdea8f0f96e110862

vp8/encoder/rdopt.c

diff --git a/vp8/encoder/rdopt.c b/vp8/encoder/rdopt.c
index 7b5c8e1..6dcc189 100644
--- a/vp8/encoder/rdopt.c
+++ b/vp8/encoder/rdopt.c
@@ -1584,8 +1584,8 @@
 
         ta0 = *(a + vp8_block2above[ib]);
         ta1 = *(a + vp8_block2above[ib + 1]);
-        tl0 = *(l + vp8_block2above[ib]);
-        tl1 = *(l + vp8_block2above[ib + 4]);
+        tl0 = *(l + vp8_block2left[ib]);
+        tl1 = *(l + vp8_block2left[ib + 4]);
         rate_t = cost_coeffs(x, xd->block + ib, PLANE_TYPE_Y_WITH_DC,
                              &ta0, &tl0, TX_4X4);
         rate_t += cost_coeffs(x, xd->block + ib + 1, PLANE_TYPE_Y_WITH_DC,