ringtest: fix an assert statement

There is an || vs && typo so the assert can never be triggered.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

tools/virtio/ringtest/main.c

@@ -86,7 +86,7 @@ void set_affinity(const char *arg)
 	cpu = strtol(arg, &endptr, 0);
 	assert(!*endptr);
 
-	assert(cpu >= 0 || cpu < CPU_SETSIZE);
+	assert(cpu >= 0 && cpu < CPU_SETSIZE);
 
 	self = pthread_self();
 	CPU_ZERO(&cpuset);