Add missing word to comment in joinrels.c.

Author: Amit Langote
Backpatch-through: 13
Discussion: https://postgr.es/m/CA%2BHiwqGQNbtamQ_9DU3osR1XiWR4wxWFZurPmN6zgbdSZDeWmw%40mail.gmail.com

src/backend/optimizer/path/joinrels.c

@@ -1619,9 +1619,9 @@ compute_partition_bounds(PlannerInfo *root, RelOptInfo *rel1,
 
 		/*
 		 * See if the partition bounds for inputs are exactly the same, in
-		 * which case we don't need to work hard: the join rel have the same
+		 * which case we don't need to work hard: the join rel will have the
-		 * partition bounds as inputs, and the partitions with the same
+		 * same partition bounds as inputs, and the partitions with the same
-		 * cardinal positions form the pairs.
+		 * cardinal positions will form the pairs.
 		 *
 		 * Note: even in cases where one or both inputs have merged bounds, it
 		 * would be possible for both the bounds to be exactly the same, but