busybox-config.inc: Fix build when DISTRO_FEATURES lacks "largefile".

busybox-config.inc: Fix build when DISTRO_FEATURES lacks "largefile".

mipsel-oe-linux-uclibc-gcc -march=mips32 -Wp,-MD,util-linux/.fdisk.o.d   -std=gnu99 -Iinclude -Ilibbb  -include include/autoconf.h -D_GNU_SOURCE -DNDEBUG  -D"BB_VER=KBUILD_STR(1.17.3)" -DBB_BT=AUTOCONF_TIMESTAMP  -Wall -Wshadow -Wwrite-strings -Wundef -Wstrict-prototypes -Wunused -Wunused-parameter -Wunused-function -Wunused-value -Wmissing-prototypes -Wmissing-declarations -Wdeclaration-after-statement -Wold-style-definition -fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer -ffunction-sections -fdata-sections -fno-guess-branch-probability -funsigned-char -static-libgcc -falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1 -Os -isystem/mnt/oe/tmp/sysroots/mipsel-oe-linux-uclibc/include -fexpensive-optimizations -fomit-frame-pointer -frename-registers -Os -isystem/mnt/oe/tmp/sysroots/mipsel-oe-linux-uclibc/include -fexpensive-optimizations -fomit-frame-pointer -frename-registers -Os   -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(fdisk)"  -D"KBUIL
D_MODNAME=KBUILD_STR(fdisk)" -c -o util-linux/fdisk.o util-linux/fdisk.c
util-linux/fdisk.c: In function 'seek_sector':
util-linux/fdisk.c:522:2: error: 'off64_t' undeclared (first use in this function)
util-linux/fdisk.c:522:2: note: each undeclared identifier is reported only once for each function it appears in
util-linux/fdisk.c:522:10: error: expected ';' before 'off'
util-linux/fdisk.c:523:2: warning: implicit declaration of function 'lseek64'
util-linux/fdisk.c:523:22: error: 'off' undeclared (first use in this function)
util-linux/fdisk.c:519:22: warning: unused parameter 'secno'
make[1]: *** [util-linux/fdisk.o] Error 1
make[1]: Leaving directory `/mnt/oe/tmp/work/mipsel-oe-linux-uclibc/busybox-1.17.3-r38.1/busybox-1.17.3'
make: *** [util-linux] Error 2
make: *** Waiting for unfinished jobs....

Signed-off-by: Graham Gower <graham.gower@gmail.com>
Signed-off-by: Eric Bénard <eric@eukrea.com>