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/service_indicators.cpp b/extensions/openpower-pels/service_indicators.cpp
index 9572f25..8826276 100644
--- a/extensions/openpower-pels/service_indicators.cpp
+++ b/extensions/openpower-pels/service_indicators.cpp
@@ -15,11 +15,10 @@
  */
 #include "service_indicators.hpp"
 
-#include <fmt/format.h>
-
 #include <phosphor-logging/log.hpp>
 
 #include <bitset>
+#include <format>
 
 namespace openpower::pels::service_indicators
 {
@@ -96,7 +95,7 @@
         catch (const std::exception& e)
         {
             log<level::ERR>(
-                fmt::format("Failed to assert platform SAI LED group: {}",
+                std::format("Failed to assert platform SAI LED group: {}",
                             e.what())
                     .c_str());
         }
@@ -215,7 +214,7 @@
         }
         catch (const std::exception& e)
         {
-            log<level::ERR>(fmt::format("Could not get inventory path for "
+            log<level::ERR>(std::format("Could not get inventory path for "
                                         "location code {} ({}).",
                                         locCode, e.what())
                                 .c_str());
@@ -242,7 +241,7 @@
         catch (const std::exception& e)
         {
             log<level::INFO>(
-                fmt::format("Could not write Functional property on {} ({})",
+                std::format("Could not write Functional property on {} ({})",
                             path, e.what())
                     .c_str());
         }
@@ -261,7 +260,7 @@
         catch (const std::exception& e)
         {
             log<level::INFO>(
-                fmt::format(
+                std::format(
                     "Could not set critical association on object path {} ({})",
                     path, e.what())
                     .c_str());