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/src.cpp b/extensions/openpower-pels/src.cpp
index c9750cc..3260f20 100644
--- a/extensions/openpower-pels/src.cpp
+++ b/extensions/openpower-pels/src.cpp
@@ -26,10 +26,10 @@
 
 #include <sstream>
 #endif
-#include <fmt/format.h>
-
 #include <phosphor-logging/lg2.hpp>
 
+#include <format>
+
 namespace openpower
 {
 namespace pels
@@ -967,7 +967,7 @@
         }
         catch (const std::exception& e)
         {
-            addDebugData(fmt::format(
+            addDebugData(std::format(
                 "Error parsing PEL message registry callout JSON: {}",
                 e.what()));
         }
@@ -1059,7 +1059,7 @@
             catch (const std::exception& e)
             {
                 addDebugData(
-                    fmt::format("Could not get location code for {}: {}",
+                    std::format("Could not get location code for {}: {}",
                                 *trustedSymbolicFRUInvPath, e.what()));
                 locCode.clear();
             }
@@ -1196,7 +1196,7 @@
         }
         catch (const std::exception& e)
         {
-            auto msg = fmt::format("Unable to expand location code {}: {}",
+            auto msg = std::format("Unable to expand location code {}: {}",
                                    callout.locationCode, e.what());
             addDebugData(msg);
         }
@@ -1259,7 +1259,7 @@
         }
         catch (const std::exception& e)
         {
-            addDebugData(fmt::format(
+            addDebugData(std::format(
                 "Failed extracting callout data from JSON: {}", e.what()));
         }
     }
@@ -1284,7 +1284,7 @@
         }
         catch (const std::exception& e)
         {
-            addDebugData(fmt::format("Unable to expand location code {}: {}",
+            addDebugData(std::format("Unable to expand location code {}: {}",
                                      unexpandedLocCode, e.what()));
             // Use the value from the JSON so at least there's something
             locCode = unexpandedLocCode;
@@ -1356,7 +1356,7 @@
             catch (const std::exception& e)
             {
                 throw std::runtime_error{
-                    fmt::format("Unable to get inventory path from "
+                    std::format("Unable to get inventory path from "
                                 "location code: {}: {}",
                                 unexpandedLocCode, e.what())};
             }
@@ -1421,7 +1421,7 @@
     if (priorityIt == pv::calloutPriorityValues.end())
     {
         throw std::runtime_error{
-            fmt::format("Invalid priority '{}' found in JSON callout", p)};
+            std::format("Invalid priority '{}' found in JSON callout", p)};
     }
 
     return priority;
@@ -1457,7 +1457,7 @@
         }
         catch (const std::exception& e)
         {
-            addDebugData(fmt::format("Invalid MRU entry in JSON: {}: {}",
+            addDebugData(std::format("Invalid MRU entry in JSON: {}: {}",
                                      mruCallout.dump(), e.what()));
         }
     }