[PATCH 1/1] rasd: Use perf_evlist__open() instead of open coded

[Arnaldo Carvalho de Melo]

Heya, please check if this is OK.

This was while looking the set of methods used by rasd, trying to reduce
it to the bare minimum.

Perhaps even that cpu_map__new() one can be ditched, leaving to use the
default of a NULL cpumap that will end up being one with -1, i.e. all
cpus.

- Arnaldo