[mellanox]: Fixed config reload race

[nazariig]

Signed-off-by: Nazarii Hnydyn nazariig@mellanox.com

This PR propagates fix for config reload race:

root@sonic:/etc/sonic# config load_minigraph -y
Running command: systemctl stop dhcp_relay
Running command: systemctl stop swss
Running command: systemctl stop snmp
Warning: Stopping snmp.service, but it can still be activated by:
snmp.timer
Running command: systemctl stop lldp
Running command: systemctl stop pmon
Running command: systemctl stop bgp
Running command: systemctl stop teamd
Running command: systemctl stop hostcfgd
Running command: /usr/local/bin/sonic-cfggen -H -m -j /etc/sonic/init_cfg.json --write-to-db
Running command: pfcwd start_default
Running command: config qos reload
Running command: /usr/local/bin/sonic-cfggen -d -t /usr/share/sonic/device/x86_64-mlnx_msn2700-r0/ACS-MSN2700/buffers.json.j2 >/tmp/buffers.json
Running command: /usr/local/bin/sonic-cfggen -d -t /usr/share/sonic/device/x86_64-mlnx_msn2700-r0/ACS-MSN2700/qos.json.j2 -y /etc/sonic/sonic_version.yml >/tmp/qos.json
Running command: /usr/local/bin/sonic-cfggen -j /tmp/buffers.json --write-to-db
Running command: /usr/local/bin/sonic-cfggen -j /tmp/qos.json --write-to-db

Running command: systemctl restart hostname-config
Running command: systemctl restart interfaces-config
Running command: systemctl restart ntp-config
Running command: systemctl restart rsyslog-config
Running command: systemctl restart swss
Running command: systemctl restart bgp
Running command: systemctl restart teamd
Running command: systemctl restart pmon
Job for pmon.service canceled.

The issue was introduced by these PRs:

1. https://github.com/Azure/sonic-buildimage/pull/2639/files
2. https://github.com/Azure/sonic-buildimage/pull/2634/files

- What I did

• Fixed pmon restart race
• Removed redundant chipupen logic

- How I did it

• Added check to do pmon restart only if service is active

- How to verify it

1. config reload -y
2. systemctl restart swss

- Description for the changelog

• N/A

[nazariig]

@lguohan @jleveque please review

[lguohan]

is this needed for 201811 branch?

[nazariig]

@lguohan no, we do not need this in 201811 branch.