net/ncsi: Fix array size in dumpit handler

With CONFIG_CC_STACKPROTECTOR enabled the kernel panics as below when
parsing a NCSI_CMD_PKG_INFO command:

[  150.149711] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: 805cff08
[  150.149711]
[  150.159919] CPU: 0 PID: 1301 Comm: ncsi-netlink Not tainted 4.13.16-468cbec6d2c91239332cb91b1f0a73aafcb6f0c6 #1
[  150.170004] Hardware name: Generic DT based system
[  150.174852] [<80109930>] (unwind_backtrace) from [<80106bc4>] (show_stack+0x20/0x24)
[  150.182641] [<80106bc4>] (show_stack) from [<805d36e4>] (dump_stack+0x20/0x28)
[  150.189888] [<805d36e4>] (dump_stack) from [<801163ac>] (panic+0xdc/0x278)
[  150.196780] [<801163ac>] (panic) from [<801162cc>] (__stack_chk_fail+0x20/0x24)
[  150.204111] [<801162cc>] (__stack_chk_fail) from [<805cff08>] (ncsi_pkg_info_all_nl+0x244/0x258)
[  150.212912] [<805cff08>] (ncsi_pkg_info_all_nl) from [<804f939c>] (genl_lock_dumpit+0x3c/0x54)
[  150.221535] [<804f939c>] (genl_lock_dumpit) from [<804...