Fix encoder multi-threading mismatch for superres

AV1 encoder multi-threading mismatch for superres=2 case
hs been fixed.

BUG=aomedia:2035

Change-Id: I904f8681f335e37e1f14bc22a03dd0dafe568035

av1/encoder/picklpf.c

diff --git a/av1/encoder/picklpf.c b/av1/encoder/picklpf.c
index 461c3af..504baff 100644
--- a/av1/encoder/picklpf.c
+++ b/av1/encoder/picklpf.c
@@ -193,6 +193,7 @@
   (void)sd;
 
   lf->sharpness_level = 0;
+  cpi->td.mb.rdmult = cpi->rd.RDMULT;
 
   if (method == LPF_PICK_MINIMAL_LPF) {
     lf->filter_level[0] = 0;

av1/encoder/pickrst.c

diff --git a/av1/encoder/pickrst.c b/av1/encoder/pickrst.c
index 28b693b..d1ac8de 100644
--- a/av1/encoder/pickrst.c
+++ b/av1/encoder/pickrst.c
@@ -1266,6 +1266,7 @@
   // problem, as these elements are ignored later, but in order to quiet
   // Valgrind's warnings we initialise the array below.
   memset(rusi, 0, sizeof(*rusi) * ntiles[0]);
+  cpi->td.mb.rdmult = cpi->rd.RDMULT;
 
   RestSearchCtxt rsc;
   const int plane_start = AOM_PLANE_Y;