tools/build: tweak unused value workaround

Clang has -Wself-assign enabled by default under -Wall, which always gets -Werror'ed on this file, causing sync-compare-and-swap to be disabled by default. The generally-accepted way to spell "this value is intentionally unused," is casting it to `void`. This is accepted by both GCC and Clang with -Wall enabled: https://godbolt.org/z/qqZ9r3 Signed-off-by: George Burgess IV <gbiv@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Link: http://lkml.kernel.org/r/20200414195638.156123-1-gbiv@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: gburgessiv

tools/build/feature/test-sync-compare-and-swap.c

@@ -7,7 +7,7 @@ int main(int argc, char *argv[])
 {
 uint64_t old, new = argc;
 
-argv = argv;
+(void)argv;
 do {
 old = __sync_val_compare_and_swap(&x, 0, 0);
 } while (!__sync_bool_compare_and_swap(&x, old, new));