tools build: Remove get_current_dir_name feature check

tools build: Remove get_current_dir_name feature check

As perf no longer tests for this feature, and it was the only user,
remove the feature test.

Signed-off-by: Ian Rogers <irogers@google.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: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
[ Remove the call to main_test_get_current_dir_name() from main() in test-all.c, otherwise it will always fail ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>