perf test: Skip dlfilter test for build failures

perf test: Skip dlfilter test for build failures

For some reason, it may fail to build the dlfilter.  Let's skip the test
as it's not an error in the perf.  This can happen when you run the perf
test without source code or in a different directory.

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>