slo-controller: fix mid resource calculate formula #8570

Job	Run time
golangci-lint	4m 11s
unit-tests(Check Go modules)	30s
unit-tests(Check manifests)	40s
unit-tests(Check auto-generated codes)	2m 43s
unit-tests(Verify gofmt)	32s
unit-tests(Verify govet)	59s
unit-tests(Run Go build)	1m 11s
unit-tests(Run Go test)	4m 58s
build-and-push (koordlet)	3m 35s
build-and-push (koord-manager)	2m 16s
build-and-push (koord-scheduler)	3m 2s
build-and-push (koord-descheduler)	3m 5s
	27m 42s

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