dreport: fix procfd missing

During the execution of 'ls -Al /proc/*/fd/ 2> /dev/null', some
processes may stop, like `while true; do echo "Hello" > /dev/null; done`

Causing the ls cmd to fail, and as a result, the procfs.log will not be
collected in the dump log.

So ensure ls procfd returns success.

Tested:
1. Run `while true; do echo "Hello" > /dev/null; done` in the
background.

2. Run `set -e; while true; do ls -Al /proc/*/fd/ 2> /dev/null
|| true; done`, the command will not stop
(before the fix, the command will stop quickly).

Change-Id: I1f4e8fda000f303fd579825e0a94efdba5a097eb
Signed-off-by: Jian Zhang <zhangjian.3032@bytedance.com>