CID 1362796: Integer handling issues (NEGATIVE_RETURNS) in statistics plugin

*** CID 1362796:  Integer handling issues  (NEGATIVE_RETURNS)
/example/statistic/statistic.cc: 50 in TSPluginInit()
44     
45       int id;
46       const char name[] = "example.statistic.now";
47     
48       if (TSStatFindName(name, &id) == TS_ERROR) {
49         id = TSStatCreate(name, TS_RECORDDATATYPE_INT, TS_STAT_NON_PERSISTENT, TS_STAT_SYNC_SUM);
   CID 1362796:  Integer handling issues  (NEGATIVE_RETURNS)
   Variable "id" tests negative.
50         if (id == TS_ERROR) {
51           TSError("%s: failed to register '%s'", PLUGIN_NAME, name);
52         }
53       }
54     
55       TSError("%s: %s registered with id %d", PLUGIN_NAME, name, id);