vfs: Rename end_writeback() to clear_inode()

After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
diff --git a/mm/shmem.c b/mm/shmem.c
index f99ff3e..68412fa 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -597,7 +597,7 @@
 	}
 	BUG_ON(inode->i_blocks);
 	shmem_free_inode(inode->i_sb);
-	end_writeback(inode);
+	clear_inode(inode);
 }
 
 /*