pass writeback_control to ->write_inode

This gives the filesystem more information about the writeback that
is happening.  Trond requested this for the NFS unstable write handling,
and other filesystems might benefit from this too by beeing able to
distinguish between the different callers in more detail.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/hfsplus/super.c

@@ -87,7 +87,8 @@ bad_inode:
 	return ERR_PTR(err);
 }
 
-static int hfsplus_write_inode(struct inode *inode, int unused)
+static int hfsplus_write_inode(struct inode *inode,
+		struct writeback_control *wbc)
 {
 	struct hfsplus_vh *vhdr;
 	int ret = 0;