Rename shm_dict_init to shm_init to fix a compiler warning.

Reviewed by:	jhb
When anouncing link state changes on an 802.11 interface with a vap,
announce the change on the vap's ifnet instead of the main ifnet.  This
matches the behavior of other wireless drivers in the tree and allows the
default devd configuration to correctly start dhclient automatically after
an ndis wireless device associates.

MFC after:	2 weeks