Rather than assembling our output piecemeal lets use the same approach
as the plugin disas interface to build the disassembly string before
printing it.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220929114231.583801-34-alex.bennee@linaro.org>