MLECO-2881: Minor improvements for downloaded resources

Check could have been bypassed if the script path provided as
an argument was incorrect. Also, a minor update in the CMake
function to fix the path.

Signed-off-by: Kshitij Sisodia <kshitij.sisodia@arm.com>
Change-Id: Id3cd4027843783e3ed8700eac503e7ba3f09ad04
diff --git a/scripts/cmake/util_functions.cmake b/scripts/cmake/util_functions.cmake
index ee9eceb..25f9731 100644
--- a/scripts/cmake/util_functions.cmake
+++ b/scripts/cmake/util_functions.cmake
@@ -196,9 +196,9 @@
 
     string(JOIN "/" FILE_URL ${resource_downloaded_dir})
     execute_process(
-            COMMAND python3 ${CMAKE_SOURCE_DIR}/scripts/py/check_update_resources_downloaded.py
+            COMMAND python3 ${SCRIPTS_DIR}/py/check_update_resources_downloaded.py
             --resource_downloaded_dir ${resource_downloaded_dir}
-            --setup_script_path ${CMAKE_SOURCE_DIR}/set_up_default_resources.py
+            --setup_script_path ${SCRIPTS_DIR}/../set_up_default_resources.py
             RESULT_VARIABLE return_code
     )
     if (NOT return_code EQUAL "0")
diff --git a/scripts/py/check_update_resources_downloaded.py b/scripts/py/check_update_resources_downloaded.py
index 6408f14..c016665 100644
--- a/scripts/py/check_update_resources_downloaded.py
+++ b/scripts/py/check_update_resources_downloaded.py
@@ -60,13 +60,21 @@
 if __name__ == "__main__":
     parser = ArgumentParser()
     parser.add_argument(
-        "--resource_downloaded_dir", help="Resources downloaded directory.", type=str
-    )
+        "--resource_downloaded_dir",
+        help="Resources downloaded directory.",
+        type=str,
+        required=True)
     parser.add_argument(
-        "--setup_script_path", help="Path to set_up_default_resources.py.", type=str
-    )
+        "--setup_script_path",
+        help="Path to set_up_default_resources.py.",
+        type=str,
+        required=True)
     args = parser.parse_args()
 
+    # Check validity of script path
+    if not os.path.isfile(args.setup_script_path):
+        raise ValueError(f'Invalid script path: {args.setup_script_path}')
+
     # Check if the repo root directory is a git repository
     root_file_dir = os.path.dirname(os.path.abspath(args.setup_script_path))
     is_git_repo = os.path.exists(os.path.join(root_file_dir, ".git"))