Delay the global registration of the struct ifnet in if_alloc() until after we're certain the allocation will entierly succeed.  This fixes a leak in a fairly unlikely case.
Delay the global registration of the struct ifnet in if_alloc() until after
we're certain the allocation will entierly succeed.  This fixes a leak in a
fairly unlikely case.

Reported by:	vijay singh <vijjus at rocketmail dot com>
MFC after:	1 week

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase