locking/atomic: scripts: fix ${atomic}_sub_and_test() kerneldoc

For ${atomic}_sub_and_test() the @i parameter is the value to subtract,
not add. Fix the typo in the kerneldoc template and generate the headers
with this update.

Fixes: ad811070

 ("locking/atomic: scripts: generate kerneldoc comments")
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20240515133844.3502360-1-cmllamas@google.com