vp8_regular_quantize_b_sse2: remove dead init

Change-Id: Ide5eefadbb3cab38743a69f744a003abb37a6506
diff --git a/vp8/encoder/x86/quantize_sse2.c b/vp8/encoder/x86/quantize_sse2.c
index 291d219..f56e646 100644
--- a/vp8/encoder/x86/quantize_sse2.c
+++ b/vp8/encoder/x86/quantize_sse2.c
@@ -35,7 +35,7 @@
 void vp8_regular_quantize_b_sse2(BLOCK *b, BLOCKD *d)
 {
     char eob = 0;
-    short *zbin_boost_ptr  = b->zrun_zbin_boost;
+    short *zbin_boost_ptr;
     short *qcoeff_ptr      = d->qcoeff;
     DECLARE_ALIGNED_ARRAY(16, short, x, 16);
     DECLARE_ALIGNED_ARRAY(16, short, y, 16);