9287 dladm Segmentation Fault (core dumped) on unknown field

This patch addresses https://www.illumos.org/issues/9287 , as Gergő Mihály Doma found out the root cause was the needed termination for the list.

Before patch:
cneira@Trixie:...lumos-omnios/usr/src/cmd/dladm$ cat /home/cneira/9287-test.txt

cneira@Trixie:...lumos-omnios/usr/src/cmd/dladm$ dladm show-link -s -p -o ipackets  e1000g0                                        

130303

cneira@Trixie:...lumos-omnios/usr/src/cmd/dladm$ dladm show-link -s -p -o not_a_valid_field  e1000g0

Memory fault(coredump)
After patch : 

cneira@Trixie:...lumos-omnios/usr/src/cmd/dladm$ /build/illumos-omnios/proto/root_i386-nd/usr/sbin/dladm show-link -s -p -o ipackets  e1000g0

130461

cneira@Trixie:...lumos-omnios/usr/src/cmd/dladm$ /build/illumos-omnios/proto/root_i386-nd/usr/sbin/dladm show-link -s -p -o not_a_valid_field  e1000g0

/build/illumos-omnios/proto/root_i386-nd/usr/sbin/dladm: no valid output fields