drm: report consistent errors when checking syncobj capibility

We've been somewhat inconsistent when adding the new ioctl and
returned ENODEV instead of EOPNOTSUPPORTED upon failing the syncobj
capibility.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: ea56991 ("drm/syncobj: add transition iotcls between binary and timeline v2")
Fixes: 01d6c35 ("drm/syncobj: add support for timeline point wait v8")
Cc: Dave Airlie <airlied@redhat.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com> for the series.
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190416123048.2913-1-lionel.g.landwerlin@intel.com

drivers/gpu/drm/drm_syncobj.c

@@ -741,7 +741,7 @@ drm_syncobj_transfer_ioctl(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	if (args->pad)
 		return -EINVAL;
@@ -1092,7 +1092,7 @@ drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
 			    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |