ping: fix address binding wrt vrf

When ping_group_range is updated, 'ping' uses the DGRAM ICMP socket,
instead of an IP raw socket. In this case, 'ping' is unable to bind its
socket to a local address owned by a vrflite.

Before the patch:
$ sysctl -w net.ipv4.ping_group_range='0  2147483647'
$ ip link add blue type vrf table 10
$ ip link add foo type dummy
$ ip link set foo master blue
$ ip link set foo up
$ ip addr add 192.168.1.1/24 dev foo
$ ip addr add 2001::1/64 dev foo
$ ip vrf exec blue ping -c1 -I 192.168.1.1 192.168.1.2
ping: bind: Cannot assign requested address
$ ip vrf exec blue ping6 -c1 -I 2001::1 2001::2
ping6: bind icmp socket: Cannot assign requested address

CC: stable@vger.kernel.org
Fixes: 1b69c6d0

 ("net: Introduce L3 Master device abstraction")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>