Revert "pldm: use std::expected for instance ID allocation"

This reverts commit 70262ed7bf854b25d4b65628bc3c892ddfe9380f.

Change-Id: I1f54d6b60bf3cfa9f00764140eec6167e1e182d6
Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
diff --git a/oem/ibm/libpldmresponder/oem_ibm_handler.cpp b/oem/ibm/libpldmresponder/oem_ibm_handler.cpp
index 34e6d70..decb953 100644
--- a/oem/ibm/libpldmresponder/oem_ibm_handler.cpp
+++ b/oem/ibm/libpldmresponder/oem_ibm_handler.cpp
@@ -524,13 +524,7 @@
     eventClass->sensor_offset = sensorOffset;
     eventClass->event_state = eventState;
     eventClass->previous_event_state = prevEventState;
-    auto instanceIdResult =
-        pldm::utils::getInstanceId(instanceIdDb.next(mctp_eid));
-    if (!instanceIdResult)
-    {
-        return;
-    }
-    auto instanceId = instanceIdResult.value();
+    auto instanceId = instanceIdDb.next(mctp_eid);
     std::vector<uint8_t> requestMsg(
         sizeof(pldm_msg_hdr) + PLDM_PLATFORM_EVENT_MESSAGE_MIN_REQ_BYTES +
         sensorEventDataVec.size());