Add missing @Override

Bug: b/247076137
Change-Id: I9561a6255e5ac5a6a199d67dc5964a29d7bd384d
diff --git a/src/main/java/com/android/tools/r8/cf/code/CfInstanceFieldRead.java b/src/main/java/com/android/tools/r8/cf/code/CfInstanceFieldRead.java
index 41ce9c9..09ec0f5 100644
--- a/src/main/java/com/android/tools/r8/cf/code/CfInstanceFieldRead.java
+++ b/src/main/java/com/android/tools/r8/cf/code/CfInstanceFieldRead.java
@@ -47,6 +47,7 @@
     return true;
   }
 
+  @Override
   public CfInstanceFieldRead asInstanceFieldGet() {
     return this;
   }