Fix delta_qindex and delta_lflevel signaling

BUG=aomedia:992

Change-Id: Ifcaedaf312f056fcc29e6a8e020aac0ddc52affd
diff --git a/av1/decoder/decodemv.c b/av1/decoder/decodemv.c
index 31f99cd..b38f99f 100644
--- a/av1/decoder/decodemv.c
+++ b/av1/decoder/decodemv.c
@@ -42,8 +42,8 @@
   FRAME_COUNTS *counts = xd->counts;
   int sign, abs, reduced_delta_qindex = 0;
   BLOCK_SIZE bsize = mbmi->sb_type;
-  const int b_col = mi_col & MAX_MIB_MASK;
-  const int b_row = mi_row & MAX_MIB_MASK;
+  const int b_col = mi_col & (cm->mib_size - 1);
+  const int b_row = mi_row & (cm->mib_size - 1);
   const int read_delta_q_flag = (b_col == 0 && b_row == 0);
   int rem_bits, thr;
   int i, smallval;
@@ -84,8 +84,8 @@
   FRAME_COUNTS *counts = xd->counts;
   int sign, abs, reduced_delta_lflevel = 0;
   BLOCK_SIZE bsize = mbmi->sb_type;
-  const int b_col = mi_col & MAX_MIB_MASK;
-  const int b_row = mi_row & MAX_MIB_MASK;
+  const int b_col = mi_col & (cm->mib_size - 1);
+  const int b_row = mi_row & (cm->mib_size - 1);
   const int read_delta_lf_flag = (b_col == 0 && b_row == 0);
   int rem_bits, thr;
   int i, smallval;