net: make NET_(DEV|NS)_REFCNT_TRACKER depend on NET

It makes little sense to ask if networking namespace or net device refcount
tracking shall be enabled for debug kernel builds without network support.

This is similar to the commit eb0b39ef ("net: CONFIG_DEBUG_NET depends
on CONFIG_NET").

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220915124256.32512-1-lukas.bulwahn@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>