doc: add missing assert return types · nodejs/node@b74e0ff

Original file line number	Diff line number	Diff line change
`@@ -1097,6 +1097,7 @@ added: v10.0.0`
`1097`	`1097`	* `asyncFn` {Function\|Promise}
`1098`	`1098`	* `error` {RegExp\|Function}
`1099`	`1099`	* `message` {string}
	`1100`	`+* Returns: {Promise}`
`1100`	`1101`
`1101`	`1102`	Awaits the `asyncFn` promise or, if `asyncFn` is a function, immediately
`1102`	`1103`	`calls the function and awaits the returned promise to complete. It will then`
`@@ -2041,6 +2042,7 @@ added: v10.0.0`
`2041`	`2042`	* `asyncFn` {Function\|Promise}
`2042`	`2043`	* `error` {RegExp\|Function\|Object\|Error}
`2043`	`2044`	* `message` {string}
	`2045`	`+* Returns: {Promise}`
`2044`	`2046`
`2045`	`2047`	Awaits the `asyncFn` promise or, if `asyncFn` is a function, immediately
`2046`	`2048`	`calls the function and awaits the returned promise to complete. It will then`