drm/nouveau/hwmon: fix compilation without CONFIG_HWMON

Reported-by: Jim Davis <jim.epost@gmail.com>
Tested-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/nouveau/nouveau_hwmon.c

@@ -630,7 +630,6 @@ error:
 	hwmon->hwmon = NULL;
 	return ret;
 #else
-	hwmon->hwmon = NULL;
 	return 0;
 #endif
 }