[PATCH] revert oversized kmalloc check

As davem points out, this wasn't such a great idea. There may be some code
which does:

size = 1024*1024;
while (kmalloc(size, ...) == 0)
size /= 2;

which will now explode.

Cc: "David S. Miller" <[e-mail]>
Cc: Christoph Lameter <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

mm/slab.c

···
 	 * functions.
 	 */
 	cachep = __find_general_cachep(size, flags);
-	BUG_ON(!cachep);		/* Allocation size too large for kmalloc */
+	if (unlikely(cachep == NULL))
+		return NULL;
 	return __cache_alloc(cachep, flags);
 }
 EXPORT_SYMBOL(__kmalloc);