ip: fix punt socket overflow
ip: fix punt socket overflow

client_pathname is usually smaller than pc->caddr.sun_path. snprint()
ensures we stop at the NULL character or sizeof(sun_path) whichever
comes 1st. It also guarantees NULL character termination.

Type: fix

Change-Id: I9fc2a706beab931d50d32d03f7fafca7c6c2fb0b
Signed-off-by: Benoît Ganne <38aad8ffcfa407b890d258e568f161530f66882d@cisco.com>

FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp