perf annotate: Fix hist decay

We were only decaying the entries for the offsets that were associated
with an objdump line.

That way, when we accrued the whole instruction addr range, more than
100% was appearing in some cases in the live annotation TUI.

Fix it by not traversing the source code line at all, just iterate thru
the complete addr range decaying each one.

Reported-by: Mike Galbraith <mgalbraith@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.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-hcae5oxa22syjrnalsxz7s6n@git.kernel.org


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