rtc-svc: Fix to type of buffer_time_index[REF_FRAMES]

Type should be same as current_superframe count.

Change-Id: I3b79636085ea8e2709c98c37ccfe10d59be3fa21

av1/encoder/svc_layercontext.h

diff --git a/av1/encoder/svc_layercontext.h b/av1/encoder/svc_layercontext.h
index 885d252..bbbd07a 100644
--- a/av1/encoder/svc_layercontext.h
+++ b/av1/encoder/svc_layercontext.h
@@ -54,7 +54,7 @@
   int refresh[REF_FRAMES];
   double base_framerate;
   unsigned int current_superframe;
-  unsigned char buffer_time_index[REF_FRAMES];
+  unsigned int buffer_time_index[REF_FRAMES];
   unsigned char buffer_spatial_layer[REF_FRAMES];
   int skip_nonzeromv_last;
   int skip_nonzeromv_gf;