sysctl: Don't scan for the leaks on headers

These header allocations have life cycle till the device goes
shutdown. So, considering them as leak is false positive. Remove
them by marking kmemleak_not_leak

Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>