platform-mc: Clarify SetTID failure logging

Simplify the failure path to a single branch:
when SetTID fails, emit a specific message for devices that do not
support the command; otherwise report a general failure.

Motivation:
Remove unreachable and contradictory checks and make failure messages
clearer without altering behavior.

Change-Id: Ia8a0dfbdbc451fa2f2a173ae8b11d1dedef9fd27
Signed-off-by: Eric Yang <eric.yang.wiwynn@gmail.com>
diff --git a/platform-mc/terminus_manager.cpp b/platform-mc/terminus_manager.cpp
index 0de6ce9..bcbbb95 100644
--- a/platform-mc/terminus_manager.cpp
+++ b/platform-mc/terminus_manager.cpp
@@ -343,16 +343,17 @@
         rc = co_await setTidOverMctp(eid, tid);
         if (rc != PLDM_SUCCESS)
         {
-            lg2::error("Failed to Set terminus TID, error{ERROR}.", "ERROR",
-                       rc);
-            unmapTid(tid);
-            co_return rc;
-        }
-
-        if (rc != PLDM_SUCCESS && rc != PLDM_ERROR_UNSUPPORTED_PLDM_CMD)
-        {
-            lg2::error("Terminus {TID} does not support SetTID command.", "TID",
-                       tid);
+            if (rc == PLDM_ERROR_UNSUPPORTED_PLDM_CMD)
+            {
+                lg2::error("Terminus {TID} does not support SetTID command.",
+                           "TID", tid);
+            }
+            else
+            {
+                lg2::error(
+                    "Failed to Set terminus TID for terminus {TID}, error {ERROR}.",
+                    "TID", tid, "ERROR", rc);
+            }
             unmapTid(tid);
             co_return rc;
         }