perf comm: Remove needless headers from comm.h

There we don't need rbtree, only in comm.c, also ditch perf.h, not
needed at all.

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-vr1jnwwujh99skrgldtimpmu@git.kernel.org


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