mwifiex: use usleep_range instead of udelay

For the delay of 10 uSec or more usleep_range is prefered.
Unlike udelay, sleep_range avoids large number of undesired
interrupts.

Ref Documentation/timers/timers-howto.txt

Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/sdio.c b/drivers/net/wireless/mwifiex/sdio.c
index d39d845..fe6fbc1 100644
--- a/drivers/net/wireless/mwifiex/sdio.c
+++ b/drivers/net/wireless/mwifiex/sdio.c
@@ -583,7 +583,7 @@
 		else if ((cs & bits) == bits)
 			return 0;
 
-		udelay(10);
+		usleep_range(10, 20);
 	}
 
 	dev_err(adapter->dev, "poll card status failed, tries = %d\n",
@@ -761,7 +761,7 @@
 			if (len)
 				break;
 
-			udelay(10);
+			usleep_range(10, 20);
 		}
 
 		if (!len) {