Remove a couple of kerneldoc entries for struct members that do not exist,
addressing these warnings:
./include/net/sock.h:548: warning: Excess struct member '__sk_flags_offset' description in 'sock'
./include/net/sock.h:548: warning: Excess struct member 'sk_padding' description in 'sock'
Signed-off-by: Jonathan Corbet <corbet@lwn.net> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>