s/INTERP_FILTER/InterpFilter/

this matches style guidelines and stabilizes successive runs of
clang-format across the tree. remaining types should be address in
successive commits.

Change-Id: I6ad3f69cf0a22cb9a9b895b272195f891f71170f
diff --git a/av1/common/blockd.h b/av1/common/blockd.h
index f035bb5..f9f82e1 100644
--- a/av1/common/blockd.h
+++ b/av1/common/blockd.h
@@ -203,9 +203,9 @@
 
 // Only for INTER blocks
 #if CONFIG_DUAL_FILTER
-  INTERP_FILTER interp_filter[4];
+  InterpFilter interp_filter[4];
 #else
-  INTERP_FILTER interp_filter;
+  InterpFilter interp_filter;
 #endif
   MV_REFERENCE_FRAME ref_frame[2];
   TX_TYPE tx_type;