Merge remote-tracking branch 'torvalds/master' into perf/core

To pick up fixes and move perf/core forward, minor conflict as
perf_evlist__add_dummy() lost its 'perf_' prefix as it operates on a
'struct evlist', not on a 'struct perf_evlist', i.e. its tools/perf/
specific, it is not in libperf.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>