Pylint fixes

Author: lazar-mitrovic

substratevm/mx.substratevm/mx_substratevm.py

@@ -472,7 +472,6 @@ def javac_image_command(javac_path):
 
 
 def _native_junit(native_image, unittest_args, build_args=None, run_args=None, blacklist=None, whitelist=None, preserve_image=False):
-    unittest_args = unittest_args
     build_args = build_args or []
 
     javaProperties = {}

substratevm/mx.substratevm/mx_substratevm_benchmark.py

@@ -301,7 +301,7 @@ def extract_dacapo(dacapo_path):
         return extract_archive(dacapo_path, 'dacapo.extracted')
 
     def benchmark_resources(self, benchmark):
-        pass
+        return None
 
     def additional_lib(self, lib):
         return mx.library(lib).get_path(True)