[MOUNTMGR] Fix global symbolic link creations

They were wrongly pointing to the original target once rewritten
instead of pointing to the proper target: the device.

This notably fixes opening the MountMgr device from user
mode (to perform IOCTL calls, for instance), and might
also fix various bugs dealing with global namespaces.
This might have some various effects in ReactOS~.

drivers/filters/mountmgr/symlink.c

@@ -124,7 +124,7 @@ GlobalCreateSymbolicLink(IN PUNICODE_STRING DosName,
     }
 
     /* Then, create the symlink */
-    Status = IoCreateSymbolicLink(&GlobalName, DosName);
+    Status = IoCreateSymbolicLink(&GlobalName, DeviceName);
 
     FreePool(GlobalName.Buffer);