When we freed the cursor GPU state including the gbm_bo objects attached
to it, we didn't unset the cursor renderer private of the CRTCs of the
associated GPU. This means that HW cursor invalidation could potentially
break if a new gbm_bo happened to be allocated at the same memory
address as the previous one.
To avoid this, iterate through the CRTCs of the GPU of which the cursor
data is freed, and unset the cursor renderer private if it was the one
destroyed.
https://gitlab.gnome.org/GNOME/mutter/issues/199
944a4763f6