pg_upgrade: adjust error output to use new database list format

Commit a524f50d added
old_11_check_for_sql_identifier_data_type_usage(), but it did not use
the clearer database error list format added to the master branch in
commit 1634d361.  This commit fixes that.

Backpatch-through: master

src/bin/pg_upgrade/version.c

@@ -540,7 +540,7 @@ old_11_check_for_sql_identifier_data_type_usage(ClusterInfo *cluster)
 						 strerror(errno));
 			if (!db_used)
 			{
-				fprintf(script, "Database: %s\n", active_db->db_name);
+				fprintf(script, "In database: %s\n", active_db->db_name);
 				db_used = true;
 			}
 			fprintf(script, "  %s.%s.%s\n",