include/linux/prctl.h: derp

re-add
-#define PR_SET_VMA    0x53564d41
-# define PR_SET_VMA_ANON_NAME    0

refers to this: https://github.com/Ayysir/android_kernel_google_msm/commit/865dd388e2f2c2aefc260b8aacd0702bb006384f