It's naming is a bit unprecise: it actually is used for storing
xnestCursorFuncPtr inside a Screen. Thus rename it to
xnestScreenCursorFuncKeyRec to make it bit more clear.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1342>