src/lat_usleep.c: fix build

lat_usleep.c:125:19: error: assignment to '__sighandler_t' {aka 'void (*)(int)'} from incompatible pointer type 'void (*)(void)' [-Wincompatible-pointer-types]
  125 |     sa.sa_handler = interval;
      |                   ^
lat_usleep.c:102:1: note: 'interval' declared here
  102 | interval()

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>

Author: bkuhls

src/lat_usleep.c

@@ -99,7 +99,7 @@ bench_pselect(iter_t iterations, void *cookie)
 #endif /* _POSIX_SELECT */
 
 void
-interval()
+interval(int)
 {
     if (++caught == n) {
 	caught = 0;