i40e: Fix for division by zero

For some cases when reading from device are incorrect or image is
incorrect, this part of code causes crash due to division by zero.

Change-ID: I8961029a7a87b0a479995823ef8fcbf6471405e1
Signed-off-by: Michal Kosiarz <michal.kosiarz@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_common.c

@@ -3313,8 +3313,10 @@ static void i40e_parse_discover_capabilities(struct i40e_hw *hw, void *buff,
 	/* partition id is 1-based, and functions are evenly spread
 	 * across the ports as partitions
 	 */
+	if (hw->num_ports != 0) {
 		hw->partition_id = (hw->pf_id / hw->num_ports) + 1;
 		hw->num_partitions = num_functions / hw->num_ports;
+	}
 
 	/* additional HW specific goodies that might
 	 * someday be HW version specific