Plugin: procstat: PidFile doesn't verify process is still running

[rawkode]

Relevant telegraf.conf:

[[inputs.procstat]]
  pid_file = "/tmp/mongodb.pid"

System info:

Linux 5.x

Steps to reproduce:

1. Run mongod --pidfile=/tmp/mongodb.pid
2. Kill -9

Expected behavior:

State would change to running=0i

Actual behavior:

State continues to be running=1i

[glinton]

What telegraf version?

[Ritesh-Sharma]

Hey @glinton, mentioned issue can be reproducible with below version.

$ telegraf version
Telegraf 1.10.3 (git: HEAD 294bb66)

[danielnelson]

Closed in #5768