experiments: memcached: Fix off-by-one

experiments/memcached.shared.sh

@@ -15,7 +15,7 @@ cleanup_memcached() {
 
 start_memcached() {
     echo "Starting memcached"
-    taskset -c 0-$THREADS $MEMCACHED -u root -t $THREADS -b 16384 -c 32768 -m 10240 -o hashpower=24,no_lru_maintainer,no_lru_crawler $@ 2>&1 > /dev/null &
+    taskset -c 0-$((THREADS - 1)) $MEMCACHED -u root -t $THREADS -b 16384 -c 32768 -m 10240 -o hashpower=24,no_lru_maintainer,no_lru_crawler $@ 2>&1 > /dev/null &
     MEMCACHED_PID=$!
 }