qapi/parser: fix unused check_args_section arguments

Pylint informs us we're not using these arguments. Oops, it's
right. Correct the error message and remove the remaining unused
parameter.

Fix test output now that the error message is improved.

Fixes: e151941d1b
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210930205716.1148693-4-jsnow@redhat.com>
[Commit message formatting tweaked]
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

scripts/qapi/parser.py

@@ -753,16 +753,18 @@ class QAPIDoc:
 
     def check(self):
 
-        def check_args_section(args, info, what):
+        def check_args_section(args, what):
             bogus = [name for name, section in args.items()
                      if not section.member]
             if bogus:
                 raise QAPISemError(
                     self.info,
-                    "documented member%s '%s' %s not exist"
-                    % ("s" if len(bogus) > 1 else "",
-                       "', '".join(bogus),
-                       "do" if len(bogus) > 1 else "does"))
+                    "documented %s%s '%s' %s not exist" % (
+                        what,
+                        "s" if len(bogus) > 1 else "",
+                        "', '".join(bogus),
+                        "do" if len(bogus) > 1 else "does"
+                    ))
 
-        check_args_section(self.args, self.info, 'members')
-        check_args_section(self.features, self.info, 'features')
+        check_args_section(self.args, 'member')
+        check_args_section(self.features, 'feature')

tests/qapi-schema/doc-bad-feature.err

@@ -1 +1 @@
-doc-bad-feature.json:3: documented member 'a' does not exist
+doc-bad-feature.json:3: documented feature 'a' does not exist