scripts/gen_image_generic.sh: drop NOGRUB variable

It's not used since commit 816a9b30f6.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

scripts/gen_image_generic.sh

@@ -30,8 +30,6 @@ ROOTFSSIZE="$(($4 / 512))"
 [ -n "$PADDING" ] && dd if=/dev/zero of="$OUTPUT" bs=512 seek="$ROOTFSOFFSET" conv=notrunc count="$ROOTFSSIZE"
 dd if="$ROOTFSIMAGE" of="$OUTPUT" bs=512 seek="$ROOTFSOFFSET" conv=notrunc
 
-[ -n "$NOGRUB" ] && exit 0
-
 make_ext4fs -J -l "$KERNELSIZE" "$OUTPUT.kernel" "$KERNELDIR"
 dd if="$OUTPUT.kernel" of="$OUTPUT" bs=512 seek="$KERNELOFFSET" conv=notrunc
 rm -f "$OUTPUT.kernel"