ethdev: remove useless check in detach capability
ethdev: remove useless check in detach capability

This capability is not bound to which driver is handling the device, but
whether the bus is able to unplug it.

This check is already performed in rte_eal_dev_detach, there is no need
to do it in the ethdev layer.

Signed-off-by: Gaetan Rivet <a6b9f1aecd7707f01344f211143eb3bcaeb0c5c3@6wind.com>
Acked-by: Adrien Mazarguil <9d39ea493ca46c560334f650ac5d4b5ffbcb5cf0@6wind.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk