common/memtest.c: Distil common error reporting code
Move all of the common code for error message output into a new
function mem_test_report_failure() and convert the rest of the code to
use it.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>