perf tools: No need to cache the PMUs in ARM SPE auxtrace init routine

perf tools: No need to cache the PMUs in ARM SPE auxtrace init routine

- auxtrace_record__init() is called only once, so there is no point in
  using a static variable to cache the results of
  find_all_arm_spe_pmus(), make it local and free the results after use.

- Another reason is, even though SPE is micro-architecture dependent,
  but so far it only supports "statistical-profiling-extension-v1" and
  we have no chance to use multiple SPE's PMU events in Perf command.

So remove the useless check code to make it clear.

Signed-off-by: Wei Li <liwei391@huawei.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/20200724071111.35593-3-liwei391@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>