syncookies.c hasn't use any macro or function declared in slab.h and random.h,
Thus, these files can be removed from syncookies.c safely without
affecting the compilation of the net module.
Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>