perf tests: Don't retest sections in "Object code reading"

perf tests: Don't retest sections in "Object code reading"

We already only test each kcore map once, but on slow systems
(particularly with network filesystems) even the non-kcore maps are
slow.

The test can test the same objdump output over and over which only wastes
time. Generalize the skipping mechanism to track all DSOs and addresses
so that each section is only tested once.

On a fully loaded ARM Juno (simulating a parallel 'perf test' run) with
a network filesystem, the original runtime is:

  real  1m51.126s
  user  0m19.445s
  sys   1m15.431s

And the new runtime is:

  real  0m48.873s
  user  0m8.031s
  sys   0m32.353s

Committer testing:

  # perf test "code read"
   22: Object code reading          : Ok
  #

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>