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/mm/truncate.c b/mm/truncate.c
index e2e8a8a..353b683 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -567,7 +567,6 @@
 /**
  * truncate_pagecache - unmap and remove pagecache that has been truncated
  * @inode: inode
- * @oldsize: old file size
  * @newsize: new file size
  *
  * inode's new i_size must already be written before truncate_pagecache
@@ -580,7 +579,7 @@
  * situations such as writepage being called for a page that has already
  * had its underlying blocks deallocated.
  */
-void truncate_pagecache(struct inode *inode, loff_t oldsize, loff_t newsize)
+void truncate_pagecache(struct inode *inode, loff_t newsize)
 {
 	struct address_space *mapping = inode->i_mapping;
 	loff_t holebegin = round_up(newsize, PAGE_SIZE);
@@ -614,12 +613,8 @@
  */
 void truncate_setsize(struct inode *inode, loff_t newsize)
 {
-	loff_t oldsize;
-
-	oldsize = inode->i_size;
 	i_size_write(inode, newsize);
-
-	truncate_pagecache(inode, oldsize, newsize);
+	truncate_pagecache(inode, newsize);
 }
 EXPORT_SYMBOL(truncate_setsize);