ssh/terminal: consume data before checking for an error.

According to the io.Reader docs, Alex had it right the first time. (See
discussion on https://golang.org/cl/25355.)

Change-Id: Ib6fb9dfb99009e034263574e82d7e9d4828df38f
Reviewed-on: https://go-review.googlesource.com/35242
TryBot-Result: Gobot Gobot <gobot@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Adam Langley <agl@golang.org>
1 file changed