perf trace: Add OPT_END to option array of perf-trace

Add OPT_END to option array of perf-trace for fixing a SEGV bug when
showing perf-trace help message.

Without this patch;
 ./perf trace -h

 usage: perf trace [<options>] <command>

    -D, --dump-raw-trace  dump raw trace in ASCII
    -v, --verbose         be more verbose (show symbol address, etc)
    -f, Segmentation fault

With this patch:
 ./perf trace -h

 usage: perf trace [<options>] <command>

    -D, --dump-raw-trace  dump raw trace in ASCII
    -v, --verbose         be more verbose (show symbol address, etc)

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090821185603.11039.62109.stgit@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>