V4L/DVB (8881): gspca: After 'while (retry--) {...}', retry will be -1 but not 0.

Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NJean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/conex.c

@@ -731,13 +731,13 @@ static void cx11646_jpeg(struct gspca_dev*gspca_dev)
 	reg_w_val(gspca_dev, 0x0000, 0x00);
 	/* wait for completion */
 	retry = 50;
-	while (retry--) {
+	do {
 		reg_r(gspca_dev, 0x0002, 1);
 							/* 0x07 until 0x00 */
 		if (gspca_dev->usb_buf[0] == 0x00)
 			break;
 		reg_w_val(gspca_dev, 0x0053, 0x00);
-	}
+	} while (--retry);
 	if (retry == 0)
 		PDEBUG(D_ERR, "Damned Errors sending jpeg Table");
 	/* send the qtable now */

drivers/media/video/gspca/spca561.c

@@ -223,11 +223,11 @@ static int i2c_read(struct gspca_dev *gspca_dev, __u16 reg, __u8 mode)
 	reg_w_val(gspca_dev->dev, 0x8804, 0x92);
 	reg_w_val(gspca_dev->dev, 0x8801, reg);
 	reg_w_val(gspca_dev->dev, 0x8802, (mode | 0x01));
-	while (retry--) {
+	do {
 		reg_r(gspca_dev, 0x8803, 1);
 		if (!gspca_dev->usb_buf)
 			break;
-	}
+	} while (--retry);
 	if (retry == 0)
 		return -1;
 	reg_r(gspca_dev, 0x8800, 1);