mem_mtest: fix error reporting, allow escape with ^C

mem_mtest: fix error reporting, allow escape with ^C

The basic memtest function tries to watch for ^C after each
pattern pass as an escape mechanism, but if things are horribly
wrong, we'll be stuck in an inner loop flooding the console with
error messages and never check for ^C.  To make matters worse,
if the user waits for all the error messages to complete, we
then incorrectly report the test passed without errors.

Adding a check for ^C after any error is printed will give
the end user an escape mechanism from a console flood without
slowing down the overall test speed on a slow processor.

Also, the more extensive memtest quit after just a single error,
which is inconsistent with the normal memtest, and not useful if
if you are doing dynamic environmental impact testing, such as
heating/cooling etc.

Both tests now track the error count and report it properly
at test completion.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>