[GFS2] Use zero_user_page() in stuffed_readpage()

As suggested by Robert P. J. Day <rpjday@mindspring.com>

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Robert P. J. Day <rpjday@mindspring.com>

fs/gfs2/ops_address.c

@@ -208,11 +208,7 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 	 * so we need to supply one here. It doesn't happen often.
 	 */
 	if (unlikely(page->index)) {
-		kaddr = kmap_atomic(page, KM_USER0);
-		memset(kaddr, 0, PAGE_CACHE_SIZE);
-		kunmap_atomic(kaddr, KM_USER0);
-		flush_dcache_page(page);
-		SetPageUptodate(page);
+		zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
 		return 0;
 	}