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/ipc/mqueue.c b/ipc/mqueue.c
index 28bd64d..0032d9c 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -249,7 +249,7 @@
 	int i;
 	struct ipc_namespace *ipc_ns;
 
-	end_writeback(inode);
+	clear_inode(inode);
 
 	if (S_ISDIR(inode->i_mode))
 		return;