kernel: stack: Fix k_stack_pop api

_pend_current_thread can return any arbitrary value set by
_set_thred_return_value(), it happens that most cases set 0. This
function can not rely on this behavior otherwise it may return an
invalid value and/or not set data's value.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
1 file changed