Fix an uninitialized warning.

Change-Id: I3ac1070df2948f6d8637ade7192400be53a7675c
diff --git a/vp9/encoder/vp9_pickmode.c b/vp9/encoder/vp9_pickmode.c
index 829066c..d861f80 100644
--- a/vp9/encoder/vp9_pickmode.c
+++ b/vp9/encoder/vp9_pickmode.c
@@ -949,7 +949,8 @@
     // TODO(jingning): Skip is signalled per prediciton block not per tx block.
     rate += vp9_cost_bit(vp9_get_skip_prob(&cpi->common, xd), is_skippable);
   } else {
-    unsigned int var, sse;
+    unsigned int var = 0;
+    unsigned int sse = 0;
     model_rd_for_sb_uv(cpi, plane_bsize, x, xd, &rate, &dist, &var, &sse,
                        plane, plane);
   }