new helper: inode_unhashed()

note: for race-free uses you inode_lock held

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 29e3f40..39f44f2 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -962,7 +962,7 @@
 		 * dirty list.  Add blockdev inodes as well.
 		 */
 		if (!S_ISBLK(inode->i_mode)) {
-			if (hlist_unhashed(&inode->i_hash))
+			if (inode_unhashed(inode))
 				goto out;
 		}
 		if (inode->i_state & I_FREEING)