perf tools: Do not include escape sequences in color_vfprintf return

perf tools: Do not include escape sequences in color_vfprintf return

color_vprintf was including the length of the invisible escape sequences
in its return argument. Don't include them to make the return value
usable for indentation calculations.

v2: Add comment, rebase

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1438649408-20807-3-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>