qapi: delint using flake8

Petty style guide fixes and line length enforcement.  Not a big win, not
a big loss, but flake8 passes 100% on the qapi module, which gives us an
easy baseline to enforce hereafter.

A note on the flake8 exception: flake8 will warn on *any* bare except,
but pylint's is context-aware and will suppress the warning if you
re-raise the exception.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20201009161558.107041-9-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

scripts/qapi/schema.py

@@ -536,7 +536,7 @@ class QAPISchemaVariants:
             v.set_defined_in(name)
 
     def check(self, schema, seen):
-        if not self.tag_member: # flat union
+        if not self.tag_member:  # flat union
             self.tag_member = seen.get(c_name(self._tag_name))
             base = "'base'"
             # Pointing to the base type when not implicit would be
@@ -824,7 +824,7 @@ class QAPISchema:
         self._entity_dict = {}
         self._module_dict = OrderedDict()
         self._schema_dir = os.path.dirname(fname)
-        self._make_module(None) # built-ins
+        self._make_module(None)  # built-ins
         self._make_module(fname)
         self._predefining = True
         self._def_predefineds()
@@ -968,7 +968,9 @@ class QAPISchema:
             # But it's not tight: the disjunction need not imply it.  We
             # may end up compiling useless wrapper types.
             # TODO kill simple unions or implement the disjunction
-            assert (ifcond or []) == typ._ifcond # pylint: disable=protected-access
+
+            # pylint: disable=protected-access
+            assert (ifcond or []) == typ._ifcond
         else:
             self._def_entity(QAPISchemaObjectType(
                 name, info, None, ifcond, None, None, members, None))