tools lib traceevent: Add support for __print_array()

Since 6ea22486 ("tracing: Add array printing helper") trace can
generate traces with variable element size arrays.  Add support to
parse them.

Signed-off-by: Javi Merino <javi.merino@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1427195239-15730-1-git-send-email-javi.merino@arm.com


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