tksm: Fix cluster IP allocator metrics

JobBuild
187af778
05-13 13:35		 110027
05-13 10:23		 f2f925a6
05-13 10:21
pull-kubernetes-conformance-kind-ga-only-parallel 1529515376600158208 1529462974492708864 1525107161615568896 1525058643135827968
pull-kubernetes-dependencies 1529515376457551872 1529462974303965184 1525107161426825216 1525058642955472896
pull-kubernetes-e2e-gce-100-performance 1529515376725987328 1529462974614343680 1525107161733009408 1525058643253268480
pull-kubernetes-e2e-gce-ubuntu-containerd 1529514874126733312 1529462974341713920 1525107161460379648 1525058642989027328
pull-kubernetes-e2e-kind 1529515376533049344 1529462974413017088 1525107161540071424 1525058643060330496
pull-kubernetes-e2e-kind-ipv6 1529515376566603776 1529462974446571520 1525107161573625856 1525058643102273536
pull-kubernetes-integration 1529515376495300608 1529462974375268352 1525107161493934080 1525058643026776064
pull-kubernetes-node-e2e-containerd 1529515376667267072 1529462974564012032 1525107161686872064 1525058643202936832
pull-kubernetes-typecheck 1529515376763736064 1529462974647898112 1525107161770758144 1525058643282628608
pull-kubernetes-unit 1529515376637906944 1529462974526263296 1525107161653317632 1525058643169382400
pull-kubernetes-verify 1529515377300606976 1529462975969103872 1525107163096158208 1525058644608028672
pull-kubernetes-verify-govet-levee 1529515376793096192 1529462975142825984 1525107162257297408 1525058643790139392