drm/i915: Print return value on error

Print returned error code for better debuggability.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/7211


Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014154655.14075-1-nirmoy.das@intel.com