iptables_tests.sh: nat table can have 4 chains

It is considered by iptables_tests.sh a failure When nat table chain count is
not 3, while recent kernels can have 4 built-in chains in nat table, namely
PREROUTING, OUTPUT, POSTROUTING and INPUT.

Signed-off-by: Simon Xu <xu.simon@oracle.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
dhcpd_tests.sh: fix dhcpd.conf file paths

dhcpd_tests.sh only checks for /etc/dhcpd.conf, while in some distros the
path is /etc/dhcp/dhcpd.conf.

Signed-off-by: Simon Xu <xu.simon@oracle.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
chroot/chroot03.c: add ELOOP error value test for chroot(2)

Signed-off-by: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
chroot03: code clean up

Clean up the code.

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>