iproute2-3.6.0 assumes presence of iptables

iproute2-3.6.0 assumes presence of iptables

Hi,

When compiling iproute2-3.6.0 on a host that doesn't have iptables available, I get the following error:

gcc -Wall -Wstrict-prototypes -O2 -I../include -DRESOLVE_HOSTNAMES
-DLIBDIR=\"/usr/lib\" -DCONFDIR=\"/etc/iproute2\" -D_GNU_SOURCE
-DCONFIG_GACT -DCONFIG_GACT_PROB -DYY_NO_INPUT   -c -o em_ipset.o
em_ipset.c
em_ipset.c:26:21: fatal error: xtables.h: No such file or directory

Fixed by the following patch, which guards the building of em_ipset.o on
the presence of suitable headers.

Thanks,

Matt.