perf evsel: Fix printing of perf_event_paranoid message

perf evsel: Fix printing of perf_event_paranoid message

message is currently shown as:

  Error:
  You may not have permission to collect %sstats.
  Consider tweaking /proc/sys/kernel/perf_event_paranoid:

Note the %sstats. With patch this becomes:

  Error:
  You may not have permission to collect stats.
  Consider tweaking /proc/sys/kernel/perf_event_paranoid:

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1369526040-1368-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>