x/crypto/ssh: use BigEndian.Uint32 for decoding exit status.
x/crypto/ssh: use BigEndian.Uint32 for decoding exit status.

Change-Id: Iab40fe42454088a00abea61dfb6f368da9323eb3
Reviewed-on: https://go-review.googlesource.com/24726
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Run-TryBot: Han-Wen Nienhuys <3269a793d567baa2fa5b041e3e5e0a5039790a2f@google.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

ScriptRock/crypto,mattharden/crypto,ScriptRock/crypto,golang/crypto,golang/crypto,mattharden/crypto,golang/crypto