coretemp_freebsd: Cleanups
coretemp_freebsd: Cleanups

* Remove extraneous macro parameter that breaks compilation.
* Do not attempt to malloc(0), if no coretemp OIDs found.

Thanks to Gleb Smirnoff for the patch

arm-hpc/papi,arm-hpc/papi,arm-hpc/papi,arm-hpc/papi,arm-hpc/papi,arm-hpc/papi,arm-hpc/papi