perf evlist: Document missing --force option

Add --force to the man page.
Signed-off-by: NSihyeon Jang <uneedsihyeon@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1510842367-11011-5-git-send-email-uneedsihyeon@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-evlist.txt

@@ -20,6 +20,10 @@ OPTIONS
 --input=::
         Input file name. (default: perf.data unless stdin is a fifo)
 
+-f::
+--force::
+	Don't complain, do it.
+
 -F::
 --freq=::
 	Show just the sample frequency used for each event.