truncate: drop 'oldsize' truncate_pagecache() parameter

truncate_pagecache() doesn't care about old size since commit
cedabed49b39 ("vfs: Fix vmtruncate() regression").  Let's drop it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7bdc83d..82fdd70 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4409,7 +4409,7 @@
 		inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
 
 	if (newsize > oldsize) {
-		truncate_pagecache(inode, oldsize, newsize);
+		truncate_pagecache(inode, newsize);
 		ret = btrfs_cont_expand(inode, oldsize, newsize);
 		if (ret)
 			return ret;