When perf stat is called with very detailed events, the output doesn't
align well like below:

  $ sudo perf stat -a -ddd sleep 1

   Performance counter stats for 'system wide':

          8,020.23 msec cpu-clock                        #    7.997 CPUs utilized
             3,970      context-switches                 #  494.998 /sec
               169      cpu-migrations                   #   21.072 /sec
               586      page-faults                      #   73.065 /sec
       649,568,060      cycles                           #    0.081 GHz                      (30.42%)
       304,044,345      instructions                     #    0.47  insn per cycle           (38.40%)
        60,313,022      branches                         #    7.520 M/sec                    (38.89%)
         2,766,919      branch-misses                    #    4.59% of all branches          (39.26%)
        74,422,951      L1-dcache-loads                  #    9.279 M/sec                    (39.39%)
         8,025,568      L1-dcache-load-misses            #   10.78% of all L1-dcache accesses  (39.22%)
         3,314,995      LLC-loads                        #  413.329 K/sec                    (30.83%)
         1,225,619      LLC-load-misses                  #   36.97% of all LL-cache accesses  (30.45%)
   <not supported>      L1-icache-loads
        20,420,493      L1-icache-load-misses            #    0.00% of all L1-icache accesses  (30.29%)
        58,017,947      dTLB-loads                       #    7.234 M/sec                    (30.37%)
           704,677      dTLB-load-misses                 #    1.21% of all dTLB cache accesses  (30.27%)
           234,225      iTLB-loads                       #   29.204 K/sec                    (30.29%)
           417,166      iTLB-load-misses                 #  178.10% of all iTLB cache accesses  (30.32%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

       1.002947355 seconds time elapsed

Increase the METRIC_LEN by 3 so that it can align properly.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20221107213314.3239159-3-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>