update_state_supertx: rename a shadowed variable

Change-Id: I0e5fa71a4b7cd03c9e28b434b1ea72b090ca6772

av1/encoder/encodeframe.c

diff --git a/av1/encoder/encodeframe.c b/av1/encoder/encodeframe.c
index 9dc6a2e..e80f4e4 100644
--- a/av1/encoder/encodeframe.c
+++ b/av1/encoder/encodeframe.c
@@ -1333,8 +1333,8 @@
 #if CONFIG_DUAL_FILTER
       update_filter_type_count(td->counts, xd, mbmi);
 #else
-      const int ctx = av1_get_pred_context_switchable_interp(xd);
-      ++td->counts->switchable_interp[ctx][mbmi->interp_filter];
+      const int pred_ctx = av1_get_pred_context_switchable_interp(xd);
+      ++td->counts->switchable_interp[pred_ctx][mbmi->interp_filter];
 #endif
     }