Modify crypto_core_directory to also return a relative path

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/tests/scripts/test_psa_compliance.py b/tests/scripts/test_psa_compliance.py
index 984ddf3..57e4fbd 100755
--- a/tests/scripts/test_psa_compliance.py
+++ b/tests/scripts/test_psa_compliance.py
@@ -51,7 +51,7 @@
     in_tf_psa_crypto_repo = build_tree.looks_like_tf_psa_crypto_root(root_dir)
 
     crypto_name = build_tree.crypto_library_filename(root_dir)
-    library_subdir = build_tree.crypto_core_directory(root_dir)
+    library_subdir = build_tree.crypto_core_directory(root_dir, relative = True)
 
     crypto_lib_filename = (library_build_dir + '/' +
                            library_subdir + '/' +