simpleperf: fix callchains generated by the kernel.

The kernel stores return addrs in the callchain, but we
want the addrs of call instructions along the callchain.
So adjust callchains generated by the kernel.

Also avoid using const_cast<> in record.cpp by constructing
Record classes with non const buffers.

Bug: None.
Test: `python report_html.py --add_disassembly`.
Test: run simpleperf_unit_test.

Change-Id: I8c5f369e333ec9bc96cf5b5166ac670c3e3b5c62
6 files changed