PEL: switch fmt::format to use std::format

fmt::format is supported in the c++ std. This will
    help to remove fmt package dependency.

Change-Id: I89f0a5b67bbfe54168a20e93c989a1ae87f54503
Signed-off-by: Jayanth Othayoth <ojayanth@in.ibm.com>
diff --git a/extensions/openpower-pels/fru_identity.cpp b/extensions/openpower-pels/fru_identity.cpp
index 2e6ac9c..ca523c4 100644
--- a/extensions/openpower-pels/fru_identity.cpp
+++ b/extensions/openpower-pels/fru_identity.cpp
@@ -17,10 +17,10 @@
 
 #include "pel_values.hpp"
 
-#include <fmt/format.h>
-
 #include <phosphor-logging/log.hpp>
 
+#include <format>
+
 using namespace phosphor::logging;
 
 namespace openpower
@@ -256,7 +256,7 @@
         else
         {
             log<level::ERR>(
-                fmt::format("Invalid maintenance procedure {}", procedure)
+                std::format("Invalid maintenance procedure {}", procedure)
                     .c_str());
             strncpy(_pnOrProcedureID.data(), "INVALID",
                     _pnOrProcedureID.size());