ssh/terminal: fix a typo

Change-Id: Iafe2ebb6d37afd2a64aa72750a722d4860bb735e
Reviewed-on: https://go-review.googlesource.com/34535
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
1 file changed