Speed up serial timeout minimum from ~12ms to ~1ms

lib/termios.c

@@ -3794,9 +3794,9 @@ int  win32_serial_select(int  n,  fd_set  *readfds,  fd_set  *writefds,
                 goto end;
             }
 
-            hl_usleep(10000);
+            hl_usleep(1000);
             /* FIXME: not very accurate wrt process time */
-            timeout_usec -= 10000;
+            timeout_usec -= 1000;
 
             report("sleep...\n");