Fix incorrect routine name reference in partprune.c

Author: Yuzuko Hosoya
Discussion: https://postgr.es/m/00ac01d4774c$7feac860$7fc05920$@lab.ntt.co.jp

src/backend/partitioning/partprune.c

@@ -2400,7 +2400,7 @@ get_matching_list_bounds(PartitionPruneContext *context,
 
 
 /*
- * get_matching_range_datums
+ * get_matching_range_bounds
  *		Determine the offsets of range bounds matching the specified values,
  *		according to the semantics of the given operator strategy
  *