MDEV-24275 InnoDB persistent stats analyze forces full scan forcing lock crash

This is a fixup patch for MDEV-23991 afc9d00c

We really should read result.n_leaf_pages, which was set previously.

Analysis and fix was provided by Jukka Santala. Thanks!

Reviewed by: Marko Mäkelä

storage/innobase/dict/dict0stats.cc

@@ -1985,7 +1985,7 @@ static index_stats_t dict_stats_analyze_index(dict_index_t* index)
 	since it will be faster and will give better results. */
 
 	if (root_level == 0
-	    || N_SAMPLE_PAGES(index) * n_uniq > index->stat_n_leaf_pages) {
+	    || N_SAMPLE_PAGES(index) * n_uniq > result.n_leaf_pages) {
 
 		if (root_level == 0) {
 			DEBUG_PRINTF("  %s(): just one page,"