kmalloc zero size changes break i386

[Andi Kleen <ak@suse.de>]

qemu testing and booting test machines with i386 kernels wasn't very successfull
with recent git kernels. I got either BUGs because of failing sysfs initialization
or oopses in kmalloc, but no user land.

I bisected it down to this commit.

To reproduce: try to boot a 386 defconfig kernel, compiled with gcc 4.1, in qemu

-Andi 

6cb8f91320d3e720351c21741da795fed580b21b is first bad commit
commit 6cb8f91320d3e720351c21741da795fed580b21b
Author: Christoph Lameter <clameter@sgi.com>
Date:   Tue Jul 17 04:03:22 2007 -0700

    Slab allocators: consistent ZERO_SIZE_PTR support and NULL result semantics
    
    Define ZERO_OR_NULL_PTR macro to be able to remove the checks from the
    allocators.  Move ZERO_SIZE_PTR related stuff into slab.h.
    
    Make ZERO_SIZE_PTR work for all slab allocators and get rid of the
    WARN_ON_ONCE(size == 0) that is still remaining in SLAB.
    
    Make slub return NULL like the other allocators if a too large memory segmen
t
    is requested via __kmalloc.
    
    Signed-off-by: Christoph Lameter <clameter@sgi.com>
    Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>