Deprecate std::filesystem namespace include

Clang-tidy is complaining about our using fs = ... directives.  These
were originally added to handle boost::filesystem vs
std::experimental::filesystem vs std::filesystem between the various
compilers.  Now that we're all on std::filesystem, this redefinition can
be removed.

```
ChassisIntrusionSensor.hpp:11:11: error: namespace alias decl 'fs' is unused [misc-unused-alias-decls,-warnings-as-errors]
   11 | namespace fs = std::filesystem;
```

Tested: code compiles

Change-Id: If4b968ff9cceb4038f526321d3c7c11563ffbce9
Signed-off-by: Ed Tanous <etanous@nvidia.com>
diff --git a/src/adc/ADCSensorMain.cpp b/src/adc/ADCSensorMain.cpp
index ec38908..503b5f9 100644
--- a/src/adc/ADCSensorMain.cpp
+++ b/src/adc/ADCSensorMain.cpp
@@ -54,8 +54,6 @@
 static constexpr float pollRateDefault = 0.5;
 static constexpr float gpioBridgeSetupTimeDefault = 0.02;
 
-namespace fs = std::filesystem;
-
 static constexpr auto sensorTypes{std::to_array<const char*>({"ADC"})};
 static std::regex inputRegex(R"(in(\d+)_input)");
 
@@ -68,9 +66,9 @@
 };
 
 // filter out adc from any other voltage sensor
-bool isAdc(const fs::path& parentPath)
+bool isAdc(const std::filesystem::path& parentPath)
 {
-    fs::path namePath = parentPath / "name";
+    std::filesystem::path namePath = parentPath / "name";
 
     std::ifstream nameFile(namePath);
     if (!nameFile.good())
@@ -99,9 +97,9 @@
         [&io, &objectServer, &sensors, &dbusConnection, sensorsChanged,
          updateType](const ManagedObjectType& sensorConfigurations) {
             bool firstScan = sensorsChanged == nullptr;
-            std::vector<fs::path> paths;
-            if (!findFiles(fs::path("/sys/class/hwmon"), R"(in\d+_input)",
-                           paths))
+            std::vector<std::filesystem::path> paths;
+            if (!findFiles(std::filesystem::path("/sys/class/hwmon"),
+                           R"(in\d+_input)", paths))
             {
                 std::cerr << "No adc sensors in system\n";
                 return;