kernel: iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()

In the Linux kernel, the following vulnerability has been resolved: iscsiibft: Fix UBSAN shift-out-of-bounds warning in ibftattrshownic When performing an iSCSI boot using IPv6, iscsistart still reads the /sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix length is 64, this...