Minor cleanup in McRouteHandleProvider
Minor cleanup in McRouteHandleProvider

Summary: make code more consistent

Test Plan: mcrouter unit tests

Reviewed By: aap@fb.com

Subscribers: alikhtarov

FB internal diff: D1758177

synecdoche/mcrouter,leitao/mcrouter,reddit/mcrouter,yqzhang/mcrouter,facebook/mcrouter,easyfmxu/mcrouter,evertrue/mcrouter,leitao/mcrouter,tempbottle/mcrouter,easyfmxu/mcrouter,apinski-cavium/mcrouter,nvaller/mcrouter,facebook/mcrouter,seem-sky/mcrouter,seem-sky/mcrouter,evertrue/mcrouter,evertrue/mcrouter,reddit/mcrouter,seem-sky/mcrouter,is00hcw/mcrouter,glensc/mcrouter,synecdoche/mcrouter,reddit/mcrouter,is00hcw/mcrouter,glensc/mcrouter,is00hcw/mcrouter,apinski-cavium/mcrouter,tempbottle/mcrouter,glensc/mcrouter,seem-sky/mcrouter,nvaller/mcrouter,tempbottle/mcrouter,nvaller/mcrouter,easyfmxu/mcrouter,reddit/mcrouter,apinski-cavium/mcrouter,nvaller/mcrouter,easyfmxu/mcrouter,zhlong73/mcrouter,is00hcw/mcrouter,zhlong73/mcrouter,leitao/mcrouter,yqzhang/mcrouter,synecdoche/mcrouter,evertrue/mcrouter,synecdoche/mcrouter,tempbottle/mcrouter,glensc/mcrouter,leitao/mcrouter,apinski-cavium/mcrouter,yqzhang/mcrouter,facebook/mcrouter,yqzhang/mcrouter,facebook/mcrouter,zhlong73/mcrouter,zhlong73/mcrouter