fix fdset leakage

When found, it is obvious.  nfds calculated when allocating fdsets is
rewritten by calculation of size of fdtable, and when we are unlucky, we
try to free fdsets of wrong size.

Found due to OpenVZ resource management (User Beancounters).
Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

fs/file.c

@@ -283,11 +283,13 @@ static struct fdtable *alloc_fdtable(int nr)
 	} while (nfds <= nr);
 	new_fds = alloc_fd_array(nfds);
 	if (!new_fds)
-		goto out;
+		goto out2;
 	fdt->fd = new_fds;
 	fdt->max_fds = nfds;
 	fdt->free_files = NULL;
 	return fdt;
+out2:
+	nfds = fdt->max_fdset;
 out:
   	if (new_openset)
   		free_fdset(new_openset, nfds);