NFS: Clean up nfs_size_to_loff_t()

Use the same file size limit that lockd uses.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/nfs_fs.h

@@ -503,12 +503,10 @@ extern int  nfsroot_mount(struct sockaddr_in *, char *, struct nfs_fh *,
  * inline functions
  */
 
-static inline loff_t
-nfs_size_to_loff_t(__u64 size)
+static inline loff_t nfs_size_to_loff_t(__u64 size)
 {
-	loff_t maxsz = (((loff_t) ULONG_MAX) << PAGE_CACHE_SHIFT) + PAGE_CACHE_SIZE - 1;
-	if (size > maxsz)
-		return maxsz;
+	if (size > (__u64) OFFSET_MAX - 1)
+		return OFFSET_MAX - 1;
 	return (loff_t) size;
 }