perf test: Ignore .scale and other special files

'perf test' tries to parse all entries in /sys/devices/cpu/events/.
Ignore the special entries like '.scale', which cannot be directly
parsed as an event. This patch assumes all files containing a '.' are
special and can be ignored.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1465223766-29902-1-git-send-email-andi@firstfloor.org


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