json: Have lexer call streamer directly

json_lexer_init() takes the function to process a token as an
argument.  It's always json_message_process_token().  Makes the code
harder to understand for no actual gain.  Drop the indirection.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-34-armbru@redhat.com>
diff --git a/qobject/json-streamer.c b/qobject/json-streamer.c
index 78dfff2..9f57ebf 100644
--- a/qobject/json-streamer.c
+++ b/qobject/json-streamer.c
@@ -34,8 +34,8 @@
     }
 }
 
-static void json_message_process_token(JSONLexer *lexer, GString *input,
-                                       JSONTokenType type, int x, int y)
+void json_message_process_token(JSONLexer *lexer, GString *input,
+                                JSONTokenType type, int x, int y)
 {
     JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
     JSONToken *token;
@@ -115,7 +115,7 @@
     parser->tokens = g_queue_new();
     parser->token_size = 0;
 
-    json_lexer_init(&parser->lexer, json_message_process_token);
+    json_lexer_init(&parser->lexer);
 }
 
 void json_message_parser_feed(JSONMessageParser *parser,