We had that 'with_hits' filter to show just the build ids for DSOs that
had samples, make that generic so that we can use it in the upcoming
buildid-cache --missing feature, to show just the build ids that are not
in the cache.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-9nfesdfpnx7zp96yn3tmfbx0@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>