Auto merge of #3715 - saghm:master, r=alexcrichton
Auto merge of #3715 - saghm:master, r=alexcrichton

Fix typo in code example

tshepang/cargo,achanda/cargo,rustyhorde/cargo,nipunn1313/cargo,achanda/cargo,rustyhorde/cargo,rust-lang/cargo,nipunn1313/cargo,tsurai/cargo,vojtechkral/cargo,eminence/cargo,vojtechkral/cargo,durka/cargo,tsurai/cargo,nipunn1313/cargo,achanda/cargo,rust-lang/cargo,tsurai/cargo,tshepang/cargo,durka/cargo,eminence/cargo,durka/cargo,tshepang/cargo,rust-lang/cargo,tsurai/cargo,tshepang/cargo,tsurai/cargo,rust-lang/cargo,rustyhorde/cargo,eminence/cargo,vojtechkral/cargo,rustyhorde/cargo,durka/cargo,nipunn1313/cargo,eminence/cargo,achanda/cargo,vojtechkral/cargo