sys: FspFileNameIsValid, FspFileNameIsValidPattern: check path component length

tst: memfs: allow filenames to be 512 chars long

src/sys/file.c

@@ -1911,7 +1911,9 @@ NTSTATUS FspMainFileOpen(
     PFILE_OBJECT MainFileObject;
 
     /* assert that the supplied name is actually a main file name */
-    ASSERT(FspFileNameIsValid(MainFileName, 0, 0));
+    ASSERT(FspFileNameIsValid(MainFileName,
+        FsvolDeviceExtension->VolumeParams.MaxComponentLength,
+        0, 0));
 
     *PMainFileHandle = 0;
     *PMainFileObject = 0;