ethdev: keep count of representor ranges in API

ethdev: keep count of representor ranges in API

In its current state, the API can overflow the user-passed buffer if a new
representor range appears between function calls.

In order to solve this problem, augment the representor info structure with
the numbers of allocated and initialized ranges. This way the users of this
structure can be sure they will not overrun the buffer.

Fixes: 85e1588ca72f ("ethdev: add API to get representor info")
Cc: stable@dpdk.org
Signed-off-by: Viacheslav Galaktionov <viacheslav.galaktionov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Reviewed-by: Xueming Li <xuemingl@nvidia.com>