drm/xe/vf: fix return type in vf_migration_init_late()

drm/xe/vf: fix return type in vf_migration_init_late()

The vf_migration_init_late() function is supposed to return zero on
success and negative error codes on failure.  The error code
eventually gets propagated back to the probe() function and returned.
The problem is it's declared as type bool so it returns true on
error.  Change it to type int instead.

Fixes: 2e2dab20dd66 ("drm/xe/vf: Enable VF migration only on supported GuC versions")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patch.msgid.link/aTK9pwJ_roc8vpDi@stanley.mountain
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>