Catch PermissionError when trying to write a profile

... and re-raise it as AppArmorException so that only the actual error
(without a backtrace) gets displayed.

Fixes: https://gitlab.com/apparmor/apparmor/-/issues/282

utils/apparmor/aa.py

@@ -2277,6 +2277,7 @@ def write_profile(profile, is_attachment=False):
 
     serialize_options = {'METADATA': True, 'is_attachment': is_attachment}
     profile_string = serialize_profile(split_to_merged(aa), profile, serialize_options)
+    try:
         with NamedTemporaryFile('w', suffix='~', delete=False, dir=profile_dir) as newprof:
             if os.path.exists(prof_filename):
                 shutil.copymode(prof_filename, newprof.name)
@@ -2285,6 +2286,9 @@ def write_profile(profile, is_attachment=False):
                 # os.chmod(newprof.name, permission_600)
                 pass
             newprof.write(profile_string)
+    except PermissionError as e:
+        raise AppArmorException(e)
+
     os.rename(newprof.name, prof_filename)
 
     if profile in changed: