Acquire Giant conditionally in in_addmulti() and in_delmulti() based on whether the interface being accessed is IFF_NEEDSGIANT or not.  This avoids lock order reversals when calling into the interface ioctl handler, which could potentially lead to deadlock.
Acquire Giant conditionally in in_addmulti() and in_delmulti() based on
whether the interface being accessed is IFF_NEEDSGIANT or not.  This
avoids lock order reversals when calling into the interface ioctl
handler, which could potentially lead to deadlock.

The long term solution is to eliminate non-MPSAFE network drivers.

Discussed with:	jhb
MFC after:	1 week

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