MN10300: Don't try and #include <linux/slab.h> in lib/inflate.c from bootloader

Don't try and #include <linux/slab.h> in lib/inflate.c from the bootloader code
as linux/slab.h hauls in function defs that aren't available in the bootloader
code and may also haul in conflicting functions.

To fix this, make the inclusion of linux/slab.h contingent on NO_INFLATE_MALLOC
as are the usages of kmalloc() and kfree().

In MN10300, this causes the following errors:

In file included from include/linux/string.h:21,
                 from include/linux/bitmap.h:8,
                 from include/linux/nodemask.h:93,
                 from include/linux/mmzone.h:16,
                 from include/linux/gfp.h:4,
                 from include/linux/slab.h:12,
                 from arch/mn10300/boot/compressed/../../../../lib/inflate.c:106,
                 from arch/mn10300/boot/compressed/misc.c:170:
/warthog/am33/linux-2.6-mn10300/arch/mn10300/include/asm/string.h:19: error: conflicting types for 'memset'
arch/mn10300/boot...