perf report: Print sorted callchains per histogram entries

Use the newly created callchains radix tree to gather the chains stats
from the recorded events and then print the callchains for all of them,
sorted by hits, using the "-c" parameter with perf report.

Example:

 66.15%  [k] atm_clip_exit
            63.08%
                0xffffffffffffff80
                0xffffffff810196a8
                0xffffffff810c14c8
                0xffffffff8101a79c
                0xffffffff810194f3
                0xffffffff8106ab7f
                0xffffffff8106abe5
                0xffffffff8106acde
                0xffffffff8100d94b
                0xffffffff8153e7ea
                [...]

             1.54%
                0xffffffffffffff80
                0xffffffff810196a8
                0xffffffff810c14c8
                0xffffffff8101a79c
		[...]

Symbols are not yet resolved.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1246026481-8314-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>