Add the missing assignment of EFI_DISK_IO2_TOKEN::Token in FlushDiskEx() implementation. Without the assignment, system may hang sometimes.

Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14991 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c

@@ -1111,6 +1111,7 @@ DiskIo2FlushDiskEx (
       return Status;
     }
     Task->Signature = DISK_IO2_FLUSH_TASK_SIGNATURE;
+    Task->Token     = Token;
     Status = Private->BlockIo2->FlushBlocksEx (Private->BlockIo2, &Task->BlockIo2Token);
     if (EFI_ERROR (Status)) {
       gBS->CloseEvent (Task->BlockIo2Token.Event);