make buildkernel failed related to ip_divert module

rm -f hack.c
MAKE=/usr/obj/usr/src/make.i386/make sh /usr/src/sys/conf/newvers.sh WSK
cc -c -O -pipe -Wall -Wredundant-decls -Wnested-externs
-Wstrict-prototypes -W missing-prototypes -Wpointer-arith -Winline
-Wcast-qual -fformat-extensions -st d=c99 -nostdinc -I- -I.
-I/usr/src/sys -I/usr/src/sys/contrib/dev/acpica -I/us
r/src/sys/contrib/altq -I/usr/src/sys/contrib/ipfilter
-I/usr/src/sys/contrib/pf -I/usr/src/sys/contrib/dev/ath
-I/usr/src/sys/contrib/dev/ath/freebsd -I/usr/sr c/sys/contrib/ngatm
-D_KERNEL -include opt_global.h -fno-common -finline-limit=8 000 --param
inline-unit-growth=100 --param large-function-growth=1000 -mno-alig
n-long-strings -mpreferred-stack-boundary=2 -ffreestanding -Werror vers.c
linking kernel
ip_divert.o(.text+0x1238): In function `div_modevent':
: undefined reference to `ip_divert_ptr'
ip_divert.o(.text+0x12c2): In function `div_modevent':
: undefined reference to `ip_divert_ptr'
*** Error code 1

Stop in /usr/obj/usr/src/sys/WSK.
*** Error code 1