Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
* Improve warning message when libunwind devel packages not present, from Jiri Olsa
* Remove perf_event_attr needless version inflation, from Jiri Olsa
* Introduce libtraceevent strerror like error reporting facility, from Namhyung Kim
* Add pmu mappings to perf.data header and use event names from cmd line, from Robert Richter
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>