eCryptfs: cast page->index to loff_t instead of off_t

page->index should be cast to loff_t instead of off_t.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ecryptfs/read_write.c

@@ -87,7 +87,7 @@ int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
 	loff_t offset;
 	int rc;
 
-	offset = ((((off_t)page_for_lower->index) << PAGE_CACHE_SHIFT)
+	offset = ((((loff_t)page_for_lower->index) << PAGE_CACHE_SHIFT)
 		  + offset_in_page);
 	virt = kmap(page_for_lower);
 	rc = ecryptfs_write_lower(ecryptfs_inode, virt, offset, size);