perf metricgroup: Don't early exit if no CPUID table exists

perf metricgroup: Don't early exit if no CPUID table exists

The failure to find a table of metrics with a CPUID shouldn't early
exit as the metric code will now also consider the default table.

When searching for a metric or metric group,
pmu_metrics_table__for_each_metric() considers all tables and so the
caller doesn't need to switch the table to do this.

Fixes: c7adeb0974f18da4 ("perf jevents: Add set of common metrics based on default ones")
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Leo Yan <leo.yan@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>