igb: remove redundant count set and err_hw_init

Remove the setting of ring->count variables from igb_probe as they are
duplicating the same configuration that is done igb_alloc_queues.

Remove the err_hw_init tag as it can be replaced by err_sw_init.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>