[NET]: kernel-doc fixes

Fix kernel-doc omissions in net/:

Warning(linux-2.6.23-rc1//net/core/dev.c:2728): No description found for parameter 'addr'
Warning(linux-2.6.23-rc1//net/core/dev.c:2752): No description found for parameter 'addr'
Warning(linux-2.6.23-rc1//net/core/dev.c:3839): No description found for parameter 'net_dma'
Warning(linux-2.6.23-rc1//net/core/dev.c:3877): No description found for parameter 'state'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>