Dynamic port breakout before warm reboot would cause swss to crash.

[chiourung]

Reproduce step:

1. breakout port

root@as7726-32x-2:/# config interface breakout Ethernet0 4x10G -f -y

Running Breakout Mode : 1x100G[40G]
Target Breakout Mode : 4x10G

Ports to be deleted :
 {
    "Ethernet0": "100000"
}
Ports to be added :
 {
    "Ethernet0": "10000",
    "Ethernet1": "10000",
    "Ethernet2": "10000",
    "Ethernet3": "10000"
}
Breakout process got successfully completed.
Please note loaded setting will be lost after system reboot. To preserve setting, run `config save`.

2. reboot

Error log:

NOTICE swss#orchagent: :- bake: foundPortConfigDone = 1
NOTICE swss#orchagent: :- bake: foundPortInitDone = 1
NOTICE swss#orchagent: :- bake: m_portTable->getKeys 37
NOTICE swss#orchagent: :- bake: portCount = 32, m_portCount = 35
ERR swss#orchagent: :- bake: Invalid port table: portCount, expecting 32, got 35

The original port count is 32 and the count in "PORT_TABLE:PortConfigDone" is 34.
After breakout one port to four ports, the port count is 35, but the count in "PORT_TABLE:PortConfigDone" is not updated.