GPU-DRM: Use kmalloc_array() in drm_legacy_addbufs_pci()

A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kmalloc_array".

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/b71c8fee-8e84-9f1b-8569-f1ae8b879cc5@users.sourceforge.net

drivers/gpu/drm/drm_bufs.c

@@ -923,8 +923,9 @@ int drm_legacy_addbufs_pci(struct drm_device *dev,
 	/* Keep the original pagelist until we know all the allocations
 	 * have succeeded
 	 */
-	temp_pagelist = kmalloc((dma->page_count + (count << page_order)) *
-			       sizeof(*dma->pagelist), GFP_KERNEL);
+	temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
+				      sizeof(*dma->pagelist),
+				      GFP_KERNEL);
 	if (!temp_pagelist) {
 		kfree(entry->buflist);
 		kfree(entry->seglist);