[ci skip] change platform name (#5747)

frameworks/PHP/comet/benchmark_config.json

@@ -16,7 +16,7 @@
       "language": "PHP",
       "flavor": "PHP7",
       "orm": "Raw",
-      "platform": "comet",
+      "platform": "workerman",
       "webserver": "None",
       "os": "Linux",
       "database_os": "Linux",
@@ -37,7 +37,7 @@
       "language": "PHP",
       "flavor": "PHP7",
       "orm": "Raw",
-      "platform": "comet",
+      "platform": "workerman",
       "webserver": "None",
       "os": "Linux",
       "database_os": "Linux",