Replace b_width_log2_lookup[] with direct block size access

Replace b_width_log2_lookup[] and b_height_log2_lookup[] computation
with direct block_size_wide/high[] access.

Change-Id: I3947085d2269309aada6f6e805e8d1c58c197316
diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index 7863514..6fd0926 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -460,8 +460,8 @@
                                          uint8_t *src, int src_stride,
                                          uint8_t *dst, int dst_stride,
                                          double *hordist, double *verdist) {
-  int bw = 4 << (b_width_log2_lookup[bsize]);
-  int bh = 4 << (b_height_log2_lookup[bsize]);
+  int bw = block_size_wide[bsize];
+  int bh = block_size_high[bsize];
   unsigned int esq[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
   unsigned int var[16];
   double total = 0;