Avoid checking on non system file systems

Author: yschimke

okhttp/src/main/kotlin/okhttp3/internal/cache/CacheLock.kt

@@ -32,7 +32,11 @@ internal object CacheLock {
     fileSystem: FileSystem,
     directory: Path,
   ): Closeable {
-    return if (fileSystem == FileSystem.SYSTEM && !Platform.isAndroid) {
+    if (fileSystem != FileSystem.SYSTEM) {
+      return Closeable {}
+    }
+
+    return if (!Platform.isAndroid) {
       fileSystemLock(inMemoryLock(directory), directory)
     } else {
       inMemoryLock(directory)