drop log level for SMBus reads
drop log level for SMBus reads

Summary:
This fills up the logs at level 3, and should definitely be
lower because it is completely uninteresting.

Reviewed By: jasmeetbagga

Differential Revision: D2829494

fb-gh-sync-id: f4300a1d7ce614e56b64fd76663c71825b79781b

peterlei/fboss,neuhausler/fboss,neuhausler/fboss,peterlei/fboss,peterlei/fboss,peterlei/fboss,neuhausler/fboss,neuhausler/fboss