I believe you can set up admin inlines for items related by OneToOne (though you're limited to one in the inline "list"), so I don't think we can change the function you mention to simply not consider OneToOnes candidates. Maybe the auto-added OneToOnes that come with inheritance, but the combination of inheritance and inlines in the admin makes my head spin (not helped by the fact that it is late night here), so input from someone who better understands admin, inheritance, and inlines and how they all fit together would help. I'm not sure it would make sense to always disallow the auto-added OneToOne as being the parent link for an inline model?
If not and in the meantime even if so, you can specify an fk_name
(http://docs.djangoproject.com/en/dev/ref/contrib/admin/#fk-name) for your inline model admin:
class CPUInline(admin.TabularInline):
model = CPU
fk_name = 'computer'
That will tell the admin which ForeignKey to use for the parent link. And then you will need the patch on #10075 to fix the Cannot assign None: "CPU.item_ptr" does not allow null values
error you will get if you try to save a computer with a newly-added inline CPU.