simpleperf debug-unwind: keep all maps when generating test file.

When generating test file, it's not enough to only keep maps hit by
callstack. Because libunwindstack may need other maps to find the
start of an elf file.

Also fix the pgoff printed in SampleUnwinder.

Bug: none
Test: run simpleperf_unit_test
Change-Id: I85984dd9a53897f988fc1bf0d73002ac5cf06ce6
1 file changed