doc: fix the description of 'close' event

doc: fix the description of 'close' event · nodejs/node@9ec87dc

Original file line number	Diff line number	Diff line change
`@@ -182,7 +182,7 @@ added: v0.1.93`
`182`	`182`
`183`	`183`	* `fd` {integer} Integer file descriptor used by the ReadStream.
`184`	`184`
`185`		`-Emitted when the ReadStream's file is opened.`
	`185`	+Emitted when the `ReadStream`'s underlying file descriptor has been closed.
`186`	`186`
`187`	`187`	`### readStream.bytesRead`
`188`	`188`	`<!-- YAML`
`@@ -296,7 +296,7 @@ added: v0.1.93`
`296`	`296`
`297`	`297`	* `fd` {integer} Integer file descriptor used by the WriteStream.
`298`	`298`
`299`		`-Emitted when the WriteStream's file is opened.`
	`299`	+Emitted when the `WriteStream`'s underlying file descriptor has been closed.
`300`	`300`
`301`	`301`	`### writeStream.bytesWritten`
`302`	`302`	`<!-- YAML`