bnx2x: Semantic Validate vlan/mac changes

This is purely semantic - break the flow in which PF validates the VF
classification filtering requirement is valid into several sub-functions
for better readable code.

Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>