UPSTREAM: include/linux/kmemleak.h: needs slab.h

include/linux/kmemleak.h: In function 'kmemleak_alloc_recursive':
include/linux/kmemleak.h:43: error: 'SLAB_NOLEAKTRACE' undeclared (first use in this function)

Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(Cherry picked from commit 66f2ca7e3f59312888131546176b42d6e248558a)
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>