ip route: print route type in JSON output

ip route: print route type in JSON output

ip route generates an invalid JSON if the route type has to be printed,
eg. when detailed mode is active, or the type is different that unicast:

    $ ip -d -j -p route show
    [ {"unicast",
            "dst": "192.168.122.0/24",
            "dev": "virbr0",
            "protocol": "kernel",
            "scope": "link",
            "prefsrc": "192.168.122.1",
            "flags": [ "linkdown" ]
        } ]

    $ ip -j -p route show
    [ {"unreachable",
            "dst": "192.168.23.0/24",
            "flags": [ ]
        },{"prohibit",
            "dst": "192.168.24.0/24",
            "flags": [ ]
        },{"blackhole",
            "dst": "192.168.25.0/24",
            "flags": [ ]
        } ]

Fix it by printing the route type as the "type" attribute:

    $ ip -d -j -p route show
    [ {
            "type": "unicast",
            "dst": "default",
            "gateway": "192.168.85.1",
            "dev": "wlp3s0",
            "protocol": "dhcp",
            "scope": "global",
            "metric": 600,
            "flags": [ ]
        },{
            "type": "unreachable",
            "dst": "192.168.23.0/24",
            "protocol": "boot",
            "scope": "global",
            "flags": [ ]
        },{
            "type": "prohibit",
            "dst": "192.168.24.0/24",
            "protocol": "boot",
            "scope": "global",
            "flags": [ ]
        },{
            "type": "blackhole",
            "dst": "192.168.25.0/24",
            "protocol": "boot",
            "scope": "global",
            "flags": [ ]
        } ]

Fixes: 663c3cb23103 ("iproute: implement JSON and color output")
Acked-by: Phil Sutter <phil@nwl.cc>
Reviewed-and-tested-by: Andrea Claudi <aclaudi@redhat.com>
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>