Without this, we get to know the command failed and the exit code but
have no idea how the command failed since we don't get the output by
default.
This makes it much easier to see what went wrong and stand a chance of
fixing it.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org> Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
