perf lock: Document missing options

Add man page entry for --force.
Signed-off-by: Sihyeon Jang <uneedsihyeon@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1510837609-6277-1-git-send-email-uneedsihyeon@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-lock.txt

@@ -42,6 +42,10 @@ COMMON OPTIONS
 --dump-raw-trace::
         Dump raw trace in ASCII.
 
+-f::
+--force::
+	Don't complan, do it.
+
 REPORT OPTIONS
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