l2-population/lb/vxlan : ip neigh add command failed

we were using ip neigh add command which must be replaced by
ip neigh replace, to avoid error when creating a VM with an ip
previously used by a deleted VM

Change-Id: I2405096d5925ae37efd5f8abcc02b99cf0c9f5d3
Closes-Bug: #1282662
NSX: add missing space 'routeron'

Noticed this in the logs and figured why not add the space...

Change-Id: Idb85aab428d5bbc5c901c49d4a65e95a60a93cb4
Merge "l2-population/lb/vxlan : ip neigh add command failed"
Merge "NSX: add missing space 'routeron'"