Follow-up to MDEV-12698: Adjust some comments

The function dict_stats_update_if_needed() replaced
row_update_statistics_if_needed(). Adjust the comments accordingly.

storage/innobase/dict/dict0stats_bg.cc

@@ -280,10 +280,10 @@ dict_stats_thread_init()
 	1) the background stats gathering thread before any other latch
 	   and released without latching anything else in between (thus
 	   any level would do here)
-	2) from row_update_statistics_if_needed()
+	2) from dict_stats_update_if_needed()
 	   and released without latching anything else in between. We know
 	   that dict_sys->mutex (SYNC_DICT) is not acquired when
-	   row_update_statistics_if_needed() is called and it may be acquired
+	   dict_stats_update_if_needed() is called and it may be acquired
 	   inside that function (thus a level <=SYNC_DICT would do).
 	3) from row_drop_table_for_mysql() after dict_sys->mutex (SYNC_DICT)
 	   and dict_operation_lock (SYNC_DICT_OPERATION) have been locked

storage/innobase/include/dict0mem.h

@@ -1581,7 +1581,7 @@ struct dict_table_t {
 	/** How many rows are modified since last stats recalc. When a row is
 	inserted, updated, or deleted, we add 1 to this number; we calculate
 	new estimates for the table and the indexes if the table has changed
-	too much, see row_update_statistics_if_needed(). The counter is reset
+	too much, see dict_stats_update_if_needed(). The counter is reset
 	to zero at statistics calculation. This counter is not protected by
 	any latch, because this is only used for heuristics. */
 	ib_uint64_t				stat_modified_counter;

storage/innobase/include/dict0stats.ic

@@ -79,7 +79,7 @@ dict_stats_is_persistent_enabled(const dict_table_t* table)
 	protect the ::stat_persistent with dict_table_stats_lock() like the
 	other ::stat_ members which would be too big performance penalty,
 	especially when this function is called from
-	row_update_statistics_if_needed(). */
+	dict_stats_update_if_needed(). */
 
 	/* we rely on this read to be atomic */
 	ib_uint32_t	stat_persistent = table->stat_persistent;