net: ipv6: Print IPv6 neighbor state changes
net: ipv6: Print IPv6 neighbor state changes

In order to be able to debug IPv6 neighbor state changes,
pretty print the state names when setting the new state.

Change-Id: I64e0b4173eaa63c9715c17420a008602759aa4fa
Signed-off-by: Jukka Rissanen <f9f077d1da4c7aa947f9864fa5a28c3588f6a45d@linux.intel.com>

fbsder/zephyr,fbsder/zephyr,fbsder/zephyr,fbsder/zephyr,fbsder/zephyr