tests/tcg: fix unused variable in linux-test

tests/tcg: fix unused variable in linux-test

The latest hexagon compiler picks up that we never consume wcount.
Given the name of the #define that rcount checks against is WCOUNT_MAX
I figured the check just got missed.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221221090411.1995037-5-alex.bennee@linaro.org>
(cherry picked from commit 2bc6c79417b89c3306b724577e775f03fe61fb2e)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>