tree 032c984274c1163cf9c2e3206653692697cb12f0
parent 9e9d99dadc7fa1933b2dfbc66d34b72091674d60
author Anthony <anthonyhkf@google.com> 1698042163 +0800
committer Ed Tanous <ed@tanous.net> 1700066636 +0000

ethernet: change MTU type to size_t

Modify the type to get this working on 64-bit system.

In phosphor-dbus-interfaces, the type is `size`:
https://github.com/openbmc/phosphor-dbus-interfaces/blob/8a2674b/yaml/xyz/openbmc_project/Network/EthernetInterface.interface.yaml#L26

phoshor-networkd has this correct and no other places use.
https://github.com/openbmc/phosphor-networkd/blob/6f256bc591bec72dd1448522d941874b21145a81/src/ethernet_interface.hpp#L146

Tested:
```
Before:
 curl localhost/redfish/v1/Managers/bmc/EthernetInterfaces/eth0 -s | grep MTU
  "MTUSize": 0,
After:
 curl localhost/redfish/v1/Managers/bmc/EthernetInterfaces/eth0 -s | grep MTU
  "MTUSize": 1500,
```

Change-Id: If3506c6274d2083b61c5c27cc6d8e178495ccea0
Signed-off-by: Anthony <anthonyhkf@google.com>
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>