Update pkg/gpu/nvidia/metrics/metrics.go
Update pkg/gpu/nvidia/metrics/metrics.go

Comment fixes

Co-authored-by: Grace Gao <f6e02dbf38603f2533988c5e6c5fc90cb67dd6f1@users.noreply.github.com>
GoogleCloudPlatform/container-engine-accelerators,GoogleCloudPlatform/container-engine-accelerators,GoogleCloudPlatform/container-engine-accelerators