From: IWAMOTO Toshihiro <iwamoto@valinux.co.jp>

I found linux-2.6.0-test11 leaks memory when execve fails.  I've also
checked the bitkeeper tree and the problem seems to be unchanged.

The attached patch is a partial backout of bitkeeper rev.  1.87 of
fs/exec.c.  I guess the original change was a simple mistake.
(free_arg_pages() is a NOP when CONFIG_MMU is defined).