control:actions: Replace `speed` with `target`

Per design, references to "speed" imply the use of RPM which is not
correct when it comes to setting a fan's target which, for example,
could be in PWM. This replaces some missed references to `speed` to
`target`.

Change-Id: Ic534edf06556d7a2035d44b0f1acdc36ba56df25
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/control/json/actions/missing_owner_target.cpp b/control/json/actions/missing_owner_target.cpp
index 8d8a605..ccafdc2 100644
--- a/control/json/actions/missing_owner_target.cpp
+++ b/control/json/actions/missing_owner_target.cpp
@@ -56,12 +56,12 @@
 
 void MissingOwnerTarget::setTarget(const json& jsonObj)
 {
-    if (!jsonObj.contains("speed"))
+    if (!jsonObj.contains("target"))
     {
         throw ActionParseError{ActionBase::getName(),
-                               "Missing required speed value"};
+                               "Missing required target value"};
     }
-    _target = jsonObj["speed"].get<uint64_t>();
+    _target = jsonObj["target"].get<uint64_t>();
 }
 
 } // namespace phosphor::fan::control::json