This test seems flaky and reports attachment even when we failed to
negotiate the architecture. However the fetching of the guest
architecture will fail tripping up the gdb AttributeError which will
trigger our early no error status exit from the test
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200430190122.4592-5-alex.bennee@linaro.org>