scrips: update the update copyright script so it's compatible with wi…

…ndows

scripts/update-copyright

@@ -98,7 +98,7 @@ def get_file_list():
 
     text = subprocess.check_output(
         'git ls-tree -rz --name-only --full-tree HEAD | '
-        'xargs -0 git check-attr text -z', shell=True)
+        'git check-attr text -z --stdin', shell=True)
     text = text.rstrip(b'\0') # strip trailing NULL-byte
     for entry in chunks(text.split(b'\0'), 3):
         assert len(entry) == 3, entry
@@ -172,7 +172,7 @@ missing_copyright = []
 files = get_file_list()
 
 for filename in files:
-    with open(filename, 'r') as f:
+    with open(filename, 'r', encoding='utf-8') as f:
         try:
             text = f.read()
         except UnicodeDecodeError as e:
@@ -181,7 +181,7 @@ for filename in files:
     #newtext = replace_header_content(text)
     if newtext:
         pass
-        with open(filename, 'w') as f:
+        with open(filename, 'w', encoding='utf-8') as f:
             f.write(newtext)
     elif ignore(filename):
         continue