skb: Add documentation for skb_clone_sk
skb: Add documentation for skb_clone_sk

This change adds some documentation to the call skb_clone_sk.  This is
meant to help clarify the purpose of the function for other developers.

Signed-off-by: Alexander Duyck <af56634f9be8457194a3461ec96c497f138af4ff@intel.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs