Dont Scan I2C if Fru is Already in Table

We can avoid scanning the FRU again if the information is already in the table.

This can happen if multiple ad hoc configs have the same bus/address they need to scan but we cant dedup these configs because each scan may have different parameters.

Doing this regardless of whether this is in Deterministic Fru Scan mode.

Also need to check after the lock, as deterministic fru scanning may add that same fru to the table.

#tlbmc

PiperOrigin-RevId: 852386110
Change-Id: I94cedafee50e3f3a70059fafd72b36ef1b8b8852