Count the last block of the validation scan in a concurrent index build

heapam_index_validate_scan() reports PROGRESS_SCAN_BLOCKS_DONE as the
number of the block that the scan starts on, forgetting to count the
last block scanned.

Due to the last block not being counted, the number of blocks_done never
matched blocks_total.  This information could remain on the view for a
long time, depending on the waits done between the phases of CREATE
INDEX CONCURRENTLY or REINDEX CONCURRENTLY.

This is incorrect still purely cosmetic, so no backpatch is done.

Author: Manu <manuelreyesbravo@gmail.com>
Discussion: https://postgr.es/m/179303526069.2212386.7608335332316408826@gmail.com

src/backend/access/heap/heapam_handler.c

@@ -1931,6 +1931,10 @@ heapam_index_validate_scan(Relation heapRelation,
 		}
 	}
 
+	/* Report scan progress, one last time. */
+	pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_DONE,
+								 hscan->rs_nblocks);
+
 	table_endscan(scan);
 
 	ExecDropSingleTupleTableSlot(slot);