qapi: Minor introspect.py cleanups

Commit 7d0f982b changed generated introspection output to no longer
produce long lines in the generated .c file, but failed to adjust
comments to match.  Add some clarity that the shorter length that
matters most is the overall QMP response on the wire.

Commit 25b1ef31 triggers a pep8 formatting nit.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180827213943.33524-2-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

scripts/qapi/introspect.py

@@ -89,7 +89,6 @@ def visit_end(self):
         for typ in self._used_types:
             typ.visit(self)
         # generate C
-        # TODO can generate awfully long lines
         name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit'
         self._genh.add(mcgen('''
 #include "qapi/qmp/qlit.h"
@@ -129,8 +128,8 @@ def _use_type(self, typ):
         if typ not in self._used_types:
             self._used_types.append(typ)
         # Clients should examine commands and events, not types.  Hide
-        # type names to reduce the temptation.  Also saves a few
-        # characters.
+        # type names as integers to reduce the temptation.  Also, it
+        # saves a few characters on the wire.
         if isinstance(typ, QAPISchemaBuiltinType):
             return typ.name
         if isinstance(typ, QAPISchemaArrayType):
@@ -185,7 +184,7 @@ def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
         arg_type = arg_type or self._schema.the_empty_object_type
         ret_type = ret_type or self._schema.the_empty_object_type
         obj = {'arg-type': self._use_type(arg_type),
-               'ret-type': self._use_type(ret_type) }
+               'ret-type': self._use_type(ret_type)}
         if allow_oob:
             obj['allow-oob'] = allow_oob
         self._gen_qlit(name, 'command', obj, ifcond)