fm10k: ignore invalid multicast address entries

This change fixes an issue with adding an invalid multicast address
using the iproute2 tool (ip maddr add <MADDR> dev <dev>). The iproute2
tool and the kernel do not validate or filter the multicast addresses
when adding them to the multicast list. Thus, when synchronizing this
list with an invalid entry, the action will be aborted with an error
since the fm10k driver currently validates the list. Consequently,
multicast entries beyond the invalid one will not be processed and
communicated with the switch via the mailbox. This change makes it so
that invalid addresses will simply be skipped and allows synchronizing
the full list to proceed.

Signed-off-by: Ngai-Mint Kwan <ngai-mint.kwan@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>