net: usb: sr9700: Replace mdelay() with msleep() in sr9700_bind()

sr9700_bind() is never called in atomic context.
It calls mdelay() to busily wait, which is not necessary.
mdelay() can be replaced with msleep().

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai <[e-mail]>
Signed-off-by: Jia-Ju Bai <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/usb/sr9700.c

···
 	/* power up and reset phy */
 	sr_write_reg(dev, SR_PRR, PRR_PHY_RST);
 	/* at least 10ms, here 20ms for safe */
-	mdelay(20);
+	msleep(20);
 	sr_write_reg(dev, SR_PRR, 0);
 	/* at least 1ms, here 2ms for reading right register */
 	udelay(2 * 1000);