[PATCH v2] usb: Use memdup_user to reuse the code

["Pathak, Rahul (R.)" <rpathak@visteon.com>]

From: Rahul Pathak <rpathak@visteon.com>

Fixing coccicheck warning which recommends to use memdup_user instead
to reimplement its code, using memdup_user simplifies the code

./drivers/usb/core/devio.c:1398:11-18: WARNING opportunity for memdup_user

Changes after v1: setting isopkt=NULL for proper kfree() call

Signed-off-by: Rahul Pathak <rpathak@visteon.com>
---
 drivers/usb/core/devio.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 38ae877c..844407c 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1395,11 +1395,10 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb
 		number_of_packets = uurb->number_of_packets;
 		isofrmlen = sizeof(struct usbdevfs_iso_packet_desc) *
 				   number_of_packets;
-		isopkt = kmalloc(isofrmlen, GFP_KERNEL);
-		if (!isopkt)
-			return -ENOMEM;
-		if (copy_from_user(isopkt, iso_frame_desc, isofrmlen)) {
-			ret = -EFAULT;
+		isopkt = memdup_user(iso_frame_desc, isofrmlen);
+		if (IS_ERR(isopkt)) {
+			ret = PTR_ERR(isopkt);
+			isopkt = NULL;
 			goto error;
 		}
 		for (totlen = u = 0; u < number_of_packets; u++) {
-- 
1.9.1