drivers/gpu/drm: 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: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_bios.c

@@ -85,12 +85,11 @@ static bool radeon_read_bios(struct radeon_device *rdev)
 		pci_unmap_rom(rdev->pdev, bios);
 		return false;
 	}
-	rdev->bios = kmalloc(size, GFP_KERNEL);
+	rdev->bios = kmemdup(bios, size, GFP_KERNEL);
 	if (rdev->bios == NULL) {
 		pci_unmap_rom(rdev->pdev, bios);
 		return false;
 	}
-	memcpy(rdev->bios, bios, size);
 	pci_unmap_rom(rdev->pdev, bios);
 	return true;
 }