perf tools: Delete perf-with-kcore.sh script

It has been obsolete since the introduction of the 'perf record --kcore'
option.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20220427141946.269523-1-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>