Fixing errorperbit calculation.

Change-Id: I06e082a18dbcc6e126cf288ee769c1480e3f2f4d

vp9/encoder/vp9_rdopt.c

diff --git a/vp9/encoder/vp9_rdopt.c b/vp9/encoder/vp9_rdopt.c
index 7b17b85..b7000cc 100644
--- a/vp9/encoder/vp9_rdopt.c
+++ b/vp9/encoder/vp9_rdopt.c
@@ -285,7 +285,8 @@
   cpi->RDDIV = RDDIV_BITS;  // in bits (to multiply D by 128)
   cpi->RDMULT = vp9_compute_rd_mult(cpi, qindex);
 
-  x->errorperbit = cpi->RDMULT / RD_MULT_EPB_RATIO + (x->errorperbit == 0);
+  x->errorperbit = cpi->RDMULT / RD_MULT_EPB_RATIO;
+  x->errorperbit += (x->errorperbit == 0);
 
   vp9_set_speed_features(cpi);