Rust: fix integration test on windows

Author: Paolo Tranquilli

rust/ql/integration-tests/options/features/functions.default.expected renamed to rust/ql/integration-tests/options/features/functions.expected

@@ -1,16 +1,17 @@
 import pytest
 
+def test_default(codeql, rust):
+    codeql.database.create()
 
-@pytest.mark.parametrize("option",
+@pytest.mark.parametrize("features",
                          [
                              pytest.param(p,
                                           marks=pytest.mark.ql_test(expected=f".{e}.expected"))
                              for p, e in (
-                                 (None, "default"),
-                                 ("cargo_features=foo", "foo"),
-                                 ("cargo_features=bar", "bar"),
-                                 ("cargo_features=*", "all"),
-                                 ("cargo_features=foo,bar", "all"))
+                                 ("foo", "foo"),
+                                 ("bar", "bar"),
+                                 ("*", "all"),
+                                 ("foo,bar", "all"))
                          ])
-def test_features(codeql, rust, option):
-    codeql.database.create(extractor_option=option)
+def test_features(codeql, rust, features):
+    codeql.database.create(extractor_option=f"cargo_features={features}")