udf: fix anchor point detection
udf: fix anchor point detection

According to ECMA 167 rev.  3 (see 3/8.4.2.1), Anchor Volume Descriptor
Pointer should be recorded at two or more anchor points located at sectors
256, N, N - 256, where N - is a largest logical sector number at volume
space.

So we should always try to detect N on UDF volume before trying to find
Anchor Volume Descriptor (i.e.  calling to udf_find_anchor()).

That said, all this patch does is updates the s_last_block even if the
udf_vrs() returns positive value.

Originally written and tested by Yuri Per, ported on latest mainline by me.

Signed-off-by: Yuri Per <292823f9ffead9b01a448f0b4728fb025047207e@acronis.com>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@openvz.org>
Cc: Max Lyadvinsky <a7db05c7f3e64d4533ed3d28e2657e83bcca2ef6@acronis.com>
Cc: Vladimir Simonov <76ccae477cccbd194548522fdf7057809d65ea97@acronis.com>
Cc: Andrew Neporada <ed9c496a505f6a6281358f5ca0e1bc5430789e0b@acronis.com>
Cc: Kirill Korotaev <34c6fceca75e456f25e7e99531e2425c6c1de443@openvz.org>
Signed-off-by: Jan Kara <596727c8a0ea4db3ba2ceceedccbacd3d7b371b8@suse.cz>

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