drm/ttm: Fix accounting error when fail to get pages for pool

BugLink: http://bugs.launchpad.net/bugs/1715678

commit 9afae271 upstream.

When fail to get needed page for pool, need to put allocated pages
into pool. But current code has a miscalculation of allocated pages,
correct it.
Signed-off-by: Xiangliang.Yu <Xiangliang.Yu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/gpu/drm/ttm/ttm_page_alloc.c

@@ -612,7 +612,7 @@ static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
 		} else {
 			pr_err("Failed to fill pool (%p)\n", pool);
 			/* If we have any pages left put them to the pool. */
-			list_for_each_entry(p, &pool->list, lru) {
+			list_for_each_entry(p, &new_pages, lru) {
 				++cpages;
 			}
 			list_splice(&new_pages, &pool->list);