fs: kill block_prepare_write

__block_write_begin and block_prepare_write are identical except for slightly
different calling conventions.  Convert all callers to the __block_write_begin
calling conventions and drop block_prepare_write.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c
index 5cbb81e..adf22b4 100644
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -160,8 +160,6 @@
 
 int reiserfs_commit_write(struct file *f, struct page *page,
 			  unsigned from, unsigned to);
-int reiserfs_prepare_write(struct file *f, struct page *page,
-			   unsigned from, unsigned to);
 /*
 ** reiserfs_unpack
 ** Function try to convert tail from direct item into indirect.
@@ -200,7 +198,7 @@
 	}
 
 	/* we unpack by finding the page with the tail, and calling
-	 ** reiserfs_prepare_write on that page.  This will force a
+	 ** __reiserfs_write_begin on that page.  This will force a
 	 ** reiserfs_get_block to unpack the tail for us.
 	 */
 	index = inode->i_size >> PAGE_CACHE_SHIFT;
@@ -210,7 +208,7 @@
 	if (!page) {
 		goto out;
 	}
-	retval = reiserfs_prepare_write(NULL, page, write_from, write_from);
+	retval = __reiserfs_write_begin(page, write_from, 0);
 	if (retval)
 		goto out_unlock;