tools build: Remove leftover libcap tests that prevents fast path feature detection...

tools build: Remove leftover libcap tests that prevents fast path feature detection from working

I noticed that the fast path feature detection was failing:

  $ cat /tmp/build/perf-tools-next/feature/test-all.make.output
  /usr/bin/ld: cannot find -lcap: No such file or directory
  collect2: error: ld returned 1 exit status
  $

The patch removing the dependency (Fixes tag below) didn't remove the
detection of libcap, and as the fast path feature detection (test-all.c)
had -lcap in its Makefile link list of libraries to link, it was failing
when libcap-devel is not available, fix it by removing those leftover
files.

Fixes: e25ebda78e230283 ("perf cap: Tidy up and improve capability testing")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/Zs-gjOGFWtAvIZit@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>