use std::format instead of fmt::format

The std::format is sufficient for the uses in this repository except
for in one file (override_fan_target.cpp, since P2286 isn't supported
by GCC yet).  Switch to std::format whenever possible.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ib2576fb530a4d7ce238e1b0bd95b40b476ec2107
diff --git a/monitor/json_parser.cpp b/monitor/json_parser.cpp
index 4d06540..b5b7291 100644
--- a/monitor/json_parser.cpp
+++ b/monitor/json_parser.cpp
@@ -23,12 +23,11 @@
 #include "tach_sensor.hpp"
 #include "types.hpp"
 
-#include <fmt/format.h>
-
 #include <nlohmann/json.hpp>
 #include <phosphor-logging/log.hpp>
 
 #include <algorithm>
+#include <format>
 #include <map>
 #include <memory>
 #include <optional>
@@ -213,7 +212,7 @@
         auto deviation = fan["deviation"].get<size_t>();
         if (100 < deviation)
         {
-            auto msg = fmt::format(
+            auto msg = std::format(
                 "Invalid deviation of {} found, must be between 0 and 100",
                 deviation);
 
@@ -230,7 +229,7 @@
             if (100 < upperDeviation)
             {
                 auto msg =
-                    fmt::format("Invalid upper_deviation of {} found, must "
+                    std::format("Invalid upper_deviation of {} found, must "
                                 "be between 0 and 100",
                                 upperDeviation);
 
@@ -409,7 +408,7 @@
         }
         else if (state != "runtime")
         {
-            auto msg = fmt::format("Invalid power off state entry {}", state);
+            auto msg = std::format("Invalid power off state entry {}", state);
             log<level::ERR>(msg.c_str());
             throw std::runtime_error(msg.c_str());
         }
@@ -449,7 +448,7 @@
     else
     {
         auto msg =
-            fmt::format("Invalid power off cause {} in power off config JSON",
+            std::format("Invalid power off cause {} in power off config JSON",
                         powerOffCause);
         log<level::ERR>(msg.c_str());
         throw std::runtime_error(msg.c_str());
@@ -509,7 +508,7 @@
     }
     else
     {
-        auto msg = fmt::format("Invalid 'type' entry {} in power off config",
+        auto msg = std::format("Invalid 'type' entry {} in power off config",
                                type);
         log<level::ERR>(msg.c_str());
         throw std::runtime_error(msg.c_str());