Expected test change

New line from `rows` on line 25 to itself is formed of two smaller steps,
from `rows` on line 25 to `rows` on line 20 and then back again. These
are both from basicLocalFlowStep and are steps from a use to the next
use.

Author: owen-mc

go/ql/test/query-tests/Security/CWE-079/StoredXss.expected

@@ -1,6 +1,7 @@
 edges
 | StoredXss.go:13:21:13:31 | call to Name | StoredXss.go:13:21:13:36 | ...+... |
 | stored.go:18:3:18:28 | ... := ...[0] | stored.go:25:14:25:17 | rows |
+| stored.go:25:14:25:17 | rows | stored.go:25:14:25:17 | rows |
 | stored.go:25:14:25:17 | rows | stored.go:25:29:25:33 | &... |
 | stored.go:25:29:25:33 | &... | stored.go:25:29:25:33 | &... |
 | stored.go:25:29:25:33 | &... | stored.go:30:22:30:25 | name |