MB-48587: Fix build

Build broken by https://review.couchbase.org/c/kv_engine/+/165452.

Change-Id: I23c6af799ee23e5556ac4eb2e5a30b116d9a14ce
Reviewed-on: https://review.couchbase.org/c/kv_engine/+/165740
Reviewed-by: Dave Rigby <daver@couchbase.com>
Reviewed-by: Jim Walker <jim@couchbase.com>
Tested-by: Dave Rigby <daver@couchbase.com>

engines/ep/src/checkpoint.cc

@@ -670,14 +670,14 @@ void Checkpoint::addStats(const AddStatFn& add_stat,
                      "vb_%d:id_%" PRIu64 ":mem_usage_queue_overhead",
                      vbucketId.get(),
                      getId());
-    add_casted_stat(buf.data(), getQueueMemOverhead(), add_stat, cookie);
+    add_casted_stat(buf.data(), getMemOverheadQueue(), add_stat, cookie);
 
     checked_snprintf(buf.data(),
                      buf.size(),
                      "vb_%d:id_%" PRIu64 ":mem_usage_key_index_overhead",
                      vbucketId.get(),
                      getId());
-    add_casted_stat(buf.data(), getKeyIndexMemUsage(), add_stat, cookie);
+    add_casted_stat(buf.data(), getMemOverheadIndex(), add_stat, cookie);
 
     checked_snprintf(buf.data(),
                      buf.size(),