include/linux: printk is needed in filter.h when CONFIG_BPF_JIT is defined

for make V=1 EXTRA_CFLAGS=-W ARCH=arm allmodconfig
    printk is need when CONFIG_BPF_JIT is defined
    or it will report pr_err and print_hex_dump are implicit declaration

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>