Added audit.h from the kernel.

Just followed the recipe in I1ca996541d05b0d5927ab828a6ce49c09877ea01

Change-Id: I5713d9ce5ff62e310a694ecfbe21cad6577bcb4d
libc: Replaced O(n^2) strstr with O(n)

Took it from glibc.

Change-Id: Ide8866a8db81c3df99ebae65a0c35fe1a34679ce