perf c2c report: Decode c2c_stats for hist entries

Decoding and storing c2c_stats for each hist entry.  Changing related
function to work with c2c_* objects.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1474558645-19956-19-git-send-email-jolsa@kernel.org


[ Add '.nr_entries = 0' to the c2c_stats initialization to fix the build on older distros ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>