fix code-scanning alert

Author: erik-krogh

ql/test/type/Test.qll

@@ -13,13 +13,13 @@ string conc(Strings a, Strings b) { result = a + b }
 float floats(Floats a, Floats b) { result = a + b }
 
 class Base extends string {
-  Base() { this = ["foo"] }
+  Base() { this = "foo" }
 
   int foo() { result = 1 }
 }
 
 class Sub extends Base {
-  Sub() { this = ["bar"] }
+  Sub() { this = "bar" }
 
   int bar() { result = Base.super.foo() }
 

ql/test/type/type.expected

@@ -37,15 +37,13 @@
 | Test.qll:16:12:16:15 | this | Test.qll:15:1:19:1 | Base |
 | Test.qll:16:12:16:15 | this | Test.qll:15:1:19:1 | Base.Base |
 | Test.qll:16:12:16:15 | this | Test.qll:15:1:19:1 | Base.extends |
-| Test.qll:16:19:16:25 | Set | file://:0:0:0:0 | string |
-| Test.qll:16:20:16:24 | String | file://:0:0:0:0 | string |
+| Test.qll:16:19:16:23 | String | file://:0:0:0:0 | string |
 | Test.qll:18:15:18:20 | result | file://:0:0:0:0 | int |
 | Test.qll:18:24:18:24 | Integer | file://:0:0:0:0 | int |
 | Test.qll:22:11:22:14 | this | Test.qll:21:1:27:1 | Sub |
 | Test.qll:22:11:22:14 | this | Test.qll:21:1:27:1 | Sub.Sub |
 | Test.qll:22:11:22:14 | this | Test.qll:21:1:27:1 | Sub.extends |
-| Test.qll:22:18:22:24 | Set | file://:0:0:0:0 | string |
-| Test.qll:22:19:22:23 | String | file://:0:0:0:0 | string |
+| Test.qll:22:18:22:22 | String | file://:0:0:0:0 | string |
 | Test.qll:24:15:24:20 | result | file://:0:0:0:0 | int |
 | Test.qll:24:24:24:33 | Super | Test.qll:15:1:19:1 | Base |
 | Test.qll:24:24:24:39 | MemberCall | file://:0:0:0:0 | int |