fanotify: split version into version and metadata_len
fanotify: split version into version and metadata_len

To implement per event type optional headers we are interested in
knowing how long the metadata structure is.  This patch slits the __u32
version field into a __u8 version and a __u16 metadata_len field (with
__u8 left over).  This should allow for backwards compat ABI.

Signed-off-by: Alexey Zaytsev <43b0a921664df383e302df6eeed708d7970dfdbf@gmail.com>
[rewrote descrtion and changed object sizes and ordering - eparis]
Signed-off-by: Eric Paris <b0b36e3cd9ea4e5739ff430a3056fabf2fdb0376@redhat.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas