fix build errors due to missing slab.h

Change-Id: Idd0505e92ad517e7c147e96b777f5a1dc703d61e
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/2548
Tested-by: Mian Yousaf KAUKAB <mian.yousaf.kaukab@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
2 files changed