linux/net.h: fix kernel-doc warnings

Fix kernel-doc warnings in linux/net.h:

Warning(include/linux/net.h:151): No description found for parameter 'wq'
Warning(include/linux/net.h:151): Excess struct/union/enum/typedef member 'fasync_list' description in 'socket'
Warning(include/linux/net.h:151): Excess struct/union/enum/typedef member 'wait' description in 'socket'

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