perf trace: Remove thread summary coloring

Thread summary line coloring looks ugly.  It doesn't add much value so
remove coloring completely.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
Acked-by: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1384447410-1771-1-git-send-email-penberg@kernel.org


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