* netbsd/sys/netinet/in.c: undo interface address addition attempt,   when in_ifinit() fails.
* netbsd/sys/netinet/in.c: undo interface address addition attempt,
  when in_ifinit() fails.

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame