HID: Use kmemdup

Use kmemdup when some other buffer is immediately copied into the
allocated region.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to,size,flag;
statement S;
@@

-  to = \(kmalloc\|kzalloc\)(size,flag);
+  to = kmemdup(from,size,flag);
   if (to==NULL || ...) S
-  memcpy(to, from, size);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-core.c

@@ -653,10 +653,9 @@ int hid_parse_report(struct hid_device *device, __u8 *start,
 	if (device->driver->report_fixup)
 		device->driver->report_fixup(device, start, size);
 
-	device->rdesc = kmalloc(size, GFP_KERNEL);
+	device->rdesc = kmemdup(start, size, GFP_KERNEL);
 	if (device->rdesc == NULL)
 		return -ENOMEM;
-	memcpy(device->rdesc, start, size);
 	device->rsize = size;
 
 	parser = vmalloc(sizeof(struct hid_parser));