Grant ping_t getattr on rawip_socket

If the (sadly nearly undocumented) Linux kernel feature which allows
specific user groups to send ICMP echos without CAP_NET_RAW
(configurable with the sysctl net.ipv4.ping_group_range, available since
3.0) is used, ping needs the getattr permission of the rawip_socket
class in order to work.
Module version bump for ping rawip socket fix from Luis Ressel.