Remove unused parameters and effectless code

Change-Id: Id0d0b4ffde80f01fdaae26cffd0e7fc2bfc963d6
diff --git a/av1/common/pred_common.c b/av1/common/pred_common.c
index 9a20c95..35d0ac3 100644
--- a/av1/common/pred_common.c
+++ b/av1/common/pred_common.c
@@ -148,16 +148,13 @@
 #define CHECK_GOLDEN_OR_LAST3(ref_frame) \
   (((ref_frame) == GOLDEN_FRAME) || ((ref_frame) == LAST3_FRAME))
 
-int av1_get_reference_mode_context(const AV1_COMMON *cm,
-                                   const MACROBLOCKD *xd) {
+int av1_get_reference_mode_context(const MACROBLOCKD *xd) {
   int ctx;
   const MB_MODE_INFO *const above_mbmi = xd->above_mbmi;
   const MB_MODE_INFO *const left_mbmi = xd->left_mbmi;
   const int has_above = xd->up_available;
   const int has_left = xd->left_available;
 
-  (void)cm;
-
   // Note:
   // The mode info data structure has a one element border above and to the
   // left of the entries corresponding to real macroblocks.