perf stat: Fix default metricgroup display on hybrid

perf stat: Fix default metricgroup display on hybrid

The logic to skip output of a default metric line was firing on
Alderlake and not displaying 'TopdownL1 (cpu_atom)'. Remove the
need_full_name check as it is equivalent to the different PMU test in
the cases we care about, merge the 'if's and flip the evsel of the PMU
test. The 'if' is now basically saying, if the output matches the last
printed output then skip the output.

Before:
```
             TopdownL1 (cpu_core)                 #     11.3 %  tma_bad_speculation
                                                  #     24.3 %  tma_frontend_bound
             TopdownL1 (cpu_core)                 #     33.9 %  tma_backend_bound
                                                  #     30.6 %  tma_retiring
                                                  #     42.2 %  tma_backend_bound
                                                  #     25.0 %  tma_frontend_bound       (49.81%)
                                                  #     12.8 %  tma_bad_speculation
                                                  #     20.0 %  tma_retiring             (59.46%)
```
After:
```
             TopdownL1 (cpu_core)                 #      8.3 %  tma_bad_speculation
                                                  #     43.7 %  tma_frontend_bound
                                                  #     30.7 %  tma_backend_bound
                                                  #     17.2 %  tma_retiring
             TopdownL1 (cpu_atom)                 #     31.9 %  tma_backend_bound
                                                  #     37.6 %  tma_frontend_bound       (49.66%)
                                                  #     18.0 %  tma_bad_speculation
                                                  #     12.6 %  tma_retiring             (59.58%)
```

Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>