Rust: fix missing canonical paths

Author: aibaars

rust/ql/lib/codeql/rust/internal/PathResolution.qll

@@ -625,7 +625,7 @@ class ImplItemNode extends ImplOrTraitItemNode instanceof Impl {
     result = "<"
     or
     i = 1 and
-    result = this.getSelfCanonicalPath(c)
+    result = this.getSelfCanonicalPath(_)
     or
     if exists(this.getTraitPath())
     then

rust/ql/test/extractor-tests/canonical_path/canonical_paths.expected

@@ -29,6 +29,8 @@ canonicalPath
 | regular.rs:69:1:71:1 | fn is_number_or_letter | test::regular::is_number_or_letter |
 | regular.rs:73:1:75:1 | trait Abs | test::regular::Abs |
 | regular.rs:74:5:74:25 | fn abs | <_ as test::regular::Abs>::abs |
+| regular.rs:77:1:85:1 | impl Abs for i32 { ... } | <core::i32 as test::regular::Abs> |
+| regular.rs:78:5:84:5 | fn abs | <core::i32 as test::regular::Abs>::abs |
 canonicalPaths
 | anonymous.rs:1:1:1:26 | use ...::Trait | None | None |
 | anonymous.rs:3:1:32:1 | fn canonicals | repo::test | crate::anonymous::canonicals |