zdtm/test: Fix live/static/netns-nf dependency

This test calls iptables to set a new packet filter using a shared
library libxt_standard.so. Unfortunately, depending on the
distribution we are running on, this shared library may be stored on a
different place.

This patch allows this test to be run on Debian like systems.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

test/zdtm/live/static/netns-nf.desc

-{'flavor': 'ns uns', 'deps': [ '/bin/sh', '/sbin/iptables', '/usr/lib64/xtables/libxt_standard.so', '/usr/bin/diff' ], 'flags': 'suid'}
+{'flavor': 'ns uns', 'deps': [ '/bin/sh', '/sbin/iptables', '/usr/lib64/xtables/libxt_standard.so|/lib/xtables/libxt_standard.so', '/usr/bin/diff' ], 'flags': 'suid'}