net: fix typo

Change-Id: Icef8a21654a248666c684d5b10d0337c544ddb25
Reviewed-on: https://go-review.googlesource.com/34388Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/net/dial.go

@@ -305,7 +305,7 @@ func (d *Dialer) Dial(network, address string) (Conn, error) {
 // When using TCP, and the host in the address parameter resolves to multiple
 // network addresses, any dial timeout (from d.Timeout or ctx) is spread
 // over each consecutive dial, such that each is given an appropriate
-// faction of the time to connect.
+// fraction of the time to connect.
 // For example, if a host has 4 IP addresses and the timeout is 1 minute,
 // the connect to each single address will be given 15 seconds to complete
 // before trying the next one.