lib/stackdepot: rename stack_depot_disable

Rename stack_depot_disable to stack_depot_disabled to make its name look
similar to the names of other stack depot flags.

Also put stack_depot_disabled's definition together with the other flags.

Also rename is_stack_depot_disabled to disable_stack_depot: this name
looks more conventional for a function that processes a boot parameter.

No functional changes.

Link: https://lkml.kernel.org/r/d78a07d222e689926e5ead229e4a2e3d87dc9aa7.1676063693.git.andreyknvl@google.com


Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>