[net] Call net_addr_ntop with correct arguments

[grgustaf]

Also, replace some magic numbers with constant from Zephyr for maximum
number of characters in an IP address string.

Signed-off-by: Geoff Gustafson [email protected]

[jimmy-huang]

+1

[cuiyanx]

Verified with commit d09e4b3 on master, we can get IPv6 address with /tests/test-tcp6-server.js as server and /tests/tools/test-tcp6-client.py as client.

Log(/tests/test-tcp6-server.js):

socket information:
    socket.bufferSize: undefined
    socket.bytesRead: undefined
    socket.bytesWritten: undefined
    socket.localPort: 9876
    socket.localAddress: 2001:db8::1
    socket.remotePort: 9876
    socket.remoteAddress: 2001:db8::2
    socket.remoteFamily: IPv6

Log( TCPEchoServ6.js):

Starting TCPEchoServ6.js sample...
listening
Connected
connection made
port: 4242
family: IPv6
address: 2001:db8::1
socket.localPort: 4242
socket.localAddress: 2001:db8::1
socket.remotePort: 4242
socket.remoteAddress: 2001:db8::2
socket.remoteFamily: IPv6
Got data: hello
Socket closed