The kernel refuses mmapping an event with the inherit flag set for
something that is systemwide (cpu == -1), and the evsel layer got this
reversed at some point, fix it.

The symtom was that the --pid and --tid parameters for 'perf record' and
'perf top' returned with -EINVAL, like:

 # /tmp/build-perf/perf record -v -fo/tmp/perf.data -p 1042
   Warning:  ... trying to fall back to cpu-clock-ticks

   Fatal: failed to mmap with 22 (Invalid argument)
Reported-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>