ipmbsensor: fix clang-tidy warning

clang-tidy-20 is much more aggressive about accessing std::optional
values, even though we have plenty of fencing in this case.  Use
`value_or` to squash the clang-tidy warning.

```
../src/ipmb/IpmbSensor.cpp:165:53: error: unchecked access to optional value [bugprone-unchecked-optional-access,-warnings-as-errors]
  165 |         "sendRequest", commandAddress, netfn, lun, *initCommand, initData);
      |                                                     ^
```

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ice3ac15dc74c3193d24a03d627555244ffc0dadb
diff --git a/src/ipmb/IpmbSensor.cpp b/src/ipmb/IpmbSensor.cpp
index 658c875..a1f5db2 100644
--- a/src/ipmb/IpmbSensor.cpp
+++ b/src/ipmb/IpmbSensor.cpp
@@ -125,10 +125,7 @@
 {
     loadDefaults();
     setInitialProperties(getSubTypeUnits());
-    if (initCommand)
-    {
-        runInitCmd();
-    }
+    runInitCmd();
     read();
 }
 
@@ -151,7 +148,7 @@
 
 void IpmbSensor::runInitCmd()
 {
-    if (!initCommand)
+    if (!initCommand.has_value())
     {
         return;
     }
@@ -162,7 +159,8 @@
         },
         "xyz.openbmc_project.Ipmi.Channel.Ipmb",
         "/xyz/openbmc_project/Ipmi/Channel/Ipmb", "org.openbmc.Ipmb",
-        "sendRequest", commandAddress, netfn, lun, *initCommand, initData);
+        "sendRequest", commandAddress, netfn, lun, initCommand.value_or(0),
+        initData);
 }
 
 void IpmbSensor::loadDefaults()