net/sysctl: use cpumask_parse in flow_limit_cpu_sysctl

cpumask_parse_user works on __user pointers, so this is wrong now.

Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Reported-by: build test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1 file changed