sock_fprog and sock_fprog_kern are of equal size, however
it's cleaner to just use sizeof(*fprog) instead to always
have correct type.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>