Include the name of the #define being tested for in the compiler
error produced when a check_define test is run and fails. This
appears only in the config.log, but it does make it a little easier
to debug problems by inspecting config.log.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>