f2fs: clean up with get_current_nat_page

Just cleanup, no logic change.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/node.c

@@ -112,25 +112,22 @@ static void clear_node_page_dirty(struct page *page)
 
 static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
 {
-	pgoff_t index = current_nat_addr(sbi, nid);
-	return f2fs_get_meta_page_nofail(sbi, index);
+	return f2fs_get_meta_page_nofail(sbi, current_nat_addr(sbi, nid));
 }
 
 static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
 {
 	struct page *src_page;
 	struct page *dst_page;
-	pgoff_t src_off;
 	pgoff_t dst_off;
 	void *src_addr;
 	void *dst_addr;
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 
-	src_off = current_nat_addr(sbi, nid);
-	dst_off = next_nat_addr(sbi, src_off);
+	dst_off = next_nat_addr(sbi, current_nat_addr(sbi, nid));
 
 	/* get current nat block page with lock */
-	src_page = f2fs_get_meta_page(sbi, src_off);
+	src_page = get_current_nat_page(sbi, nid);
 	dst_page = f2fs_grab_meta_page(sbi, dst_off);
 	f2fs_bug_on(sbi, PageDirty(src_page));