Staging dinput-scancode fix

[DodoGTA GT]

Hello

Here's a better regression fix for the dinput-scancode
patchset (the 0001 patch of that patchset caused NFS
Underground to segfault since Wine 9.15 with the addition
of a keycode loop in keyboard_create_device() because of
DIPROP_SCANCODE stuff); I modified the existing 0001
patch to solve this by copying the duplicate object checks
to that new loop (maybe I should create a separate 0003
patch to show the changes better?)

Hopefully the patch can be merged before 9.16 to not
re-introduce that regression after it has been worked
around in wine-staging 9.15

Thanks