qjson: Abort earlier on qobject_from_jsonf() misuse

Ignoring errors first, then asserting success is suboptimal.  Pass
&error_abort instead, so we abort earlier, and hopefully get more
useful clues on what's wrong.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-11-git-send-email-armbru@redhat.com>

qobject/qjson.c

@@ -65,7 +65,7 @@ QObject *qobject_from_jsonf(const char *string, ...)
     va_list ap;
 
     va_start(ap, string);
-    obj = qobject_from_jsonv(string, &ap, NULL);
+    obj = qobject_from_jsonv(string, &ap, &error_abort);
     va_end(ap);
 
     assert(obj != NULL);