perf lock contention: Add --output option

To avoid formatting failures for example in CSV output due to debug
messages, add --output option to put the result in a file.
Unfortunately the short -o option was taken by the --owner already.

  $ sudo ./perf lock con -ab --output lock-out.txt -v sleep 1
  Looking at the vmlinux_path (8 entries long)
  symsrc__init: cannot get elf header.
  Using /proc/kcore for kernel data
  Using /proc/kallsyms for symbols

  $ head lock-out.txt
   contended   total wait     max wait     avg wait         type   caller

           3     76.79 us     26.89 us     25.60 us     rwlock:R   ep_poll_callback+0x2d
  			0xffffffff9a23f4b5  _raw_read_lock_irqsave+0x45
  			0xffffffff99bbd4dd  ep_poll_callback+0x2d
  			0xffffffff999029f3  __wake_up_common+0x73
  			0xffffffff99902b82  __wake_up_common_lock+0x82
  			0xffffffff99fa5b1c  sock_def_readable+0x3c
  			0xffffffff9a11521d  unix_stream_sendmsg+0x18d
  			0xffffffff99f9fc9c  sock_sendmsg+0x5c

Suggested-by: Ian Rogers <irogers@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230628200141.2739587-4-namhyung@kernel.org


Signed-off-by: Namhyung Kim <namhyung@kernel.org>