Update CHANGELOG.md

Co-authored-by: Aki Nitta <[email protected]>

Author: DuYicong515

CHANGELOG.md

@@ -518,7 +518,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Deprecated `ParallelPlugin.torch_distributed_backend` in favor of `DDPStrategy.process_group_backend` property ([#11745](https://github.com/PyTorchLightning/pytorch-lightning/pull/11745))
 
 
-- Deprecated `Trainer.root_gpu` in favor of `Trainer.strategy.root_device.index` when GPU is used. ([#12262](https://github.com/PyTorchLightning/pytorch-lightning/pull/11978))
+- Deprecated `Trainer.root_gpu` in favor of `Trainer.strategy.root_device.index` when GPU is used. ([#12262](https://github.com/PyTorchLightning/pytorch-lightning/pull/12262))
 
 
 ### Removed