qapi: Drop superfluous qapi_enum_parse() parameter max

The lookup tables have a sentinel, no need to make callers pass their
size.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-3-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Rebased, commit message corrected]

tests/qmp-test.c

@@ -182,8 +182,7 @@ static void test_query(const void *data)
     } else {
         g_assert(error);
         g_assert_cmpint(qapi_enum_parse(QapiErrorClass_lookup, error_class,
-                                        QAPI_ERROR_CLASS__MAX, -1,
-                                        &error_abort),
+                                        -1, &error_abort),
                         ==, expected_error_class);
     }
     QDECREF(resp);