tree ac2a28a702cedb5119c08a1de183b307eea605ae
parent 5611d5485a9543c7a745814d8d7bdaf4dc1b7836
author Willy Tu <wltu@google.com> 1648506315 -0700
committer Ed Tanous <ed@tanous.net> 1651508002 +0000

storage: Call function only if interfaces exist

Avoid making the dbus call if the interface does not exist and is
expected to error out to reduce the number of dbus calls.

Tested:
Redfish Validator passed for Drives
```
$  wget -qO- \
  http://localhost:80/redfish/v1/Systems/system/Storage/1/Drives/drive
{
  "@odata.id": "/redfish/v1/Systems/system/Storage/1/Drives/drive",
  "@odata.type": "#Drive.v1_7_0.Drive",
  "Id": "warthog",
  "Links": {
    "Chassis": {
      "@odata.id": "/redfish/v1/Chassis/chassis"
    }
  },
  "Manufacturer": "XXX",
  "MediaType": "SSD",
  "Model": "XXX",
  "Name": "drive",
  "PartNumber": "xxxxxxxxxxxxx",
  "Protocol": "SATA",
  "SerialNumber": "123456",
  "Status": {
    "Health": "OK",
    "HealthRollup": "OK",
    "State": "Enabled"
  }
}
```

Change-Id: Ic83c8ee5a49f75b71d443781faf8b65d8fab31b6
Signed-off-by: Willy Tu <wltu@google.com>