perf top: Show info message while collecting samples

Give visual cue about what is happening while initially collecting the
minimal set of samples to collect/sort/display.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-xcui60p1v6ozijfam2o89ya8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1 file changed