iris: Fix return of xe_batch_submit() when exec fails

iris: Fix return of xe_batch_submit() when exec fails

When intel_ioctl(DRM_IOCTL_XE_EXEC) fails it returns -1 sets errno
with the fail reason.
This fail reason is than is used to know if engine was banned in
context_or_engine_was_banned().

Not adding a fixes tag because Xe is not enabled by default.

Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23139>