media: dvb-usb-v2/gl861: use usleep_range() for short delay

As the kernel doc "timers-howto.txt" reads,
short delay with msleep() can take much longer.
In a case of raspbery-pi platform where CONFIG_HZ_100 was set,
it actually affected the init of Friio devices
since it issues lots of i2c transactions with short delay.
Signed-off-by: NAkihiro Tsukada <tskd08@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/usb/dvb-usb-v2/gl861.c

@@ -43,7 +43,7 @@ static int gl861_i2c_msg(struct dvb_usb_device *d, u8 addr,
 		return -EINVAL;
 	}
 
-	msleep(1); /* avoid I2C errors */
+	usleep_range(1000, 2000); /* avoid I2C errors */
 
 	return usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), req, type,
 			       value, index, rbuf, rlen, 2000);