[fdb]cli: fdb entries are cleared according to vlan or port or vlan&&port

[yangshp1987]

Fdb entries can be deleted with user specifying vlan or port or vlan&&port.
fdborch is in charge of deleting fdb entries in another issues#1064,and it had pull request.

- What I did

- How I did it

- How to verify it

- Previous command output (if the output of a command-line utility has changed)

- New command output (if the output of a command-line utility has changed)

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[prsunny]

Can you provide the output of the command before/after the fix in description?

[yangshp1987]

Can you provide the output of the command before/after the fix in description?

OK，I will provide it later.
@prsunny

the output of the command **before** the fix:

root@sonic:/home/admin# bcmcmd "l2 show"
l2 show
mac=00:8c:fa:c7:ae:b8 vlan=1 GPORT=0x0 modid=0 port=0/cpu0 Static CPU
mac=00:00:00:00:00:01 vlan=1001 GPORT=0x7 modid=0 port=7/ce6 ReplacePriority
drivshell>
root@sonic:/home/admin# fdbclear -p Ethernet24 -v Vlan1001
command not supported yet.
root@sonic:/home/admin# bcmcmd "l2 show"
l2 show
mac=00:8c:fa:c7:ae:b8 vlan=1 GPORT=0x0 modid=0 port=0/cpu0 Static CPU
mac=00:00:00:00:00:01 vlan=1001 GPORT=0x7 modid=0 port=7/ce6 ReplacePriority

the output of the command **after** the fix:

root@sonic:/home/admin# cp /usr/bin/fdbclear.new /usr/bin/fdbclear
root@sonic:/home/admin# fdbclear -p Ethernet24 -v Vlan1001
Port Ethernet24 + VlanVlan1001 FDB entries are cleared.
root@sonic:/home/admin# bcmcmd "l2 show"
l2 show
mac=00:8c:fa:c7:ae:b8 vlan=1 GPORT=0x0 modid=0 port=0/cpu0 Static CPU
drivshell>

[yangshp1987]

@prsunny Could you please review，thanks.