Small clean ups

- Remove redundant map_info checks.
- Initialize fde_count_ to zero.

Bug: 23762183

Contributed-By: Ivan Maidanski <i.maidanski@samsung.com>

Test: Builds, run backtrace_test modifying CreateNew to Create and vice-versa.
Change-Id: I6e9cdfa99734f8cc2d9915cc32c66a1455e79f1b