update recent addition to 5.0 syntax

motivation: support 5.0 clients

changes: return value epxlicitly

Author: tomerd

.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug",
+            "program": "${workspaceFolder}/<executable file>",
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        }
+    ]
+}

.vscode/settings.json

@@ -0,0 +1 @@
+{}

Sources/Logging/Logging.swift

@@ -734,7 +734,7 @@ public enum LoggingSystem {
     /// but an attempt was made to set a metadata provider on such handler. In order to avoid flooding the system with
     /// warnings such warning is only emitted in debug mode, and even then at-most once for a handler type.
     internal static func warnOnceLogHandlerNotSupportedMetadataProvider<Handler: LogHandler>(_ type: Handler.Type) -> Bool {
-        self._warnOnceBox.warnOnceLogHandlerNotSupportedMetadataProvider(type: type)
+        return self._warnOnceBox.warnOnceLogHandlerNotSupportedMetadataProvider(type: type)
     }
     #endif
 
@@ -1515,8 +1515,9 @@ private final class WarnOnceBox {
     private let lock: Lock = Lock()
     private var warnOnceLogHandlerNotSupportedMetadataProviderPerType: [ObjectIdentifier: Bool] = [:]
 
+    @discardableResult
     func warnOnceLogHandlerNotSupportedMetadataProvider<Handler: LogHandler>(type: Handler.Type) -> Bool {
-        self.lock.withLock {
+        return self.lock.withLock {
             let id = ObjectIdentifier(type)
             if warnOnceLogHandlerNotSupportedMetadataProviderPerType[id] ?? false {
                 return false // don't warn, it was already warned about