net: fix kernel-doc warnings in header files

Add missing structure kernel-doc descriptions to sock.h & skbuff.h
to fix kernel-doc warnings.

(I think that Stephen H. sent a similar patch, but I can't find it.
I just want to kill the warnings, with either patch.)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/skbuff.h

@@ -232,6 +232,8 @@ typedef unsigned char *sk_buff_data_t;
  *	@mark: Generic packet mark
  *	@nfct: Associated connection, if any
  *	@ipvs_property: skbuff is owned by ipvs
+ *	@peeked: this packet has been seen already, so stats have been
+ *		done for it, don't do them again
  *	@nf_trace: netfilter packet trace flag
  *	@nfctinfo: Relationship of this skb to the connection
  *	@nfct_reasm: netfilter conntrack re-assembly pointer

include/net/sock.h

@@ -180,6 +180,7 @@ struct sock_common {
   *	@sk_sndmsg_off: cached offset for sendmsg
   *	@sk_send_head: front of stuff to transmit
   *	@sk_security: used by security modules
+  *	@sk_mark: generic packet mark
   *	@sk_write_pending: a write to stream socket waits to start
   *	@sk_state_change: callback to indicate change in the state of the sock
   *	@sk_data_ready: callback to indicate there is data to be processed