Rollup merge of #82244 - pickfire:patch-6, r=dtolnay
Rollup merge of #82244 - pickfire:patch-6, r=dtolnay

Keep consistency in example for Stdin StdinLock

Stdin uses handle whereas StdinLock uses stdin_lock, changed it to handle.

aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust