linux-user: Report error message on stderr, rather than stdout

Code change produced with:

  git ls-files linux-user | \
  xargs sed -i -E 's/(\s+)printf\s*\(("Unhandled.*)\);/\1fprintf(stderr, \2);/g'

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180706155127.7483-4-f4bug@amsat.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
5 files changed