staging: gdm72xx: Replace comparisons on jiffies values with wrap-safe functions

Fixes the following checkpatch.pl issue:

WARNING: Comparing jiffies is almost always wrong; prefer time_after,
time_before and friends
Signed-off-by: Michalis Pappas <mpappas@fastmail.fm>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gdm72xx/gdm_usb.c

@@ -730,7 +730,7 @@ static int k_mode_thread(void *arg)
 			spin_unlock_irqrestore(&k_lock, flags2);
 
 			expire = jiffies + K_WAIT_TIME;
-			while (jiffies < expire)
+			while (time_before(jiffies, expire))
 				schedule_timeout(K_WAIT_TIME);
 
 			spin_lock_irqsave(&rx->lock, flags);

drivers/staging/gdm72xx/sdio_boot.c

@@ -41,11 +41,11 @@ static u8 *tx_buf;
 
 static int ack_ready(struct sdio_func *func)
 {
-	unsigned long start = jiffies;
+	unsigned long wait = jiffies + HZ;
 	u8 val;
 	int ret;
 
-	while ((jiffies - start) < HZ) {
+	while (time_before(jiffies, wait)) {
 		val = sdio_readb(func, 0x13, &ret);
 		if (val & 0x01)
 			return 1;