ethdev: allow drivers to return error on close

ethdev: allow drivers to return error on close

The device operation .dev_close was returning void.
This driver interface is changed to return an int.

Note that the API rte_eth_dev_close() is still returning void,
although a deprecation notice is pending to change it as well.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Reviewed-by: Rosen Xu <rosen.xu@intel.com>
Reviewed-by: Sachin Saxena <sachin.saxena@oss.nxp.com>
Reviewed-by: Liron Himi <lironh@marvell.com>
Reviewed-by: Haiyue Wang <haiyue.wang@intel.com>
Acked-by: Jeff Guo <jia.guo@intel.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>