Remove unused FRAME_CONTEXT_INDEX typedef

Change-Id: I26cf6510ddc1c0534ad9ff7a40cb1aabe7f13810
diff --git a/av1/encoder/encode_strategy.c b/av1/encoder/encode_strategy.c
index 11af10f..98e26ef 100644
--- a/av1/encoder/encode_strategy.c
+++ b/av1/encoder/encode_strategy.c
@@ -250,8 +250,7 @@
 
   // Find the most recent reference frame with the same reference type as the
   // current frame
-  FRAME_CONTEXT_INDEX current_ref_type =
-      get_current_frame_ref_type(cpi, frame_params);
+  const int current_ref_type = get_current_frame_ref_type(cpi, frame_params);
   int wanted_fb = cpi->fb_of_context_type[current_ref_type];
 
   int primary_ref_frame = PRIMARY_REF_NONE;