dont need to walk alldevs during sensor creation looking for the logical disk scsibus when we record that in mfi_attach.
dont need to walk alldevs during sensor creation looking for the logical
disk scsibus when we record that in mfi_attach.

also happens to get rid of a logic error that let it come out of the loop
on alldevs with a reference to something that wasnt the logical disk
scsibus and use that.

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars