udf: remove some ugly macros

remove macros:
- UDF_SB_PARTMAPS
- UDF_SB_PARTTYPE
- UDF_SB_PARTROOT
- UDF_SB_PARTLEN
- UDF_SB_PARTVSN
- UDF_SB_PARTNUM
- UDF_SB_TYPESPAR
- UDF_SB_TYPEVIRT
- UDF_SB_PARTFUNC
- UDF_SB_PARTFLAGS
- UDF_SB_VOLIDENT
- UDF_SB_NUMPARTS
- UDF_SB_PARTITION
- UDF_SB_SESSION
- UDF_SB_ANCHOR
- UDF_SB_LASTBLOCK
- UDF_SB_LVIDBH
- UDF_SB_LVID
- UDF_SB_UMASK
- UDF_SB_GID
- UDF_SB_UID
- UDF_SB_RECORDTIME
- UDF_SB_SERIALNUM
- UDF_SB_UDFREV
- UDF_SB_FLAGS
- UDF_SB_VAT
- UDF_UPDATE_UDFREV
- UDF_SB_FREE
and open code them

convert UDF_SB_LVIDIU macro to udf_sb_lvidiu function

rename some struct udf_sb_info fields:
- s_volident to s_volume_ident
- s_lastblock to s_last_block
- s_lvidbh to s_lvid_bh
- s_recordtime to s_record_time
- s_serialnum to s_serial_number;
- s_vat to s_vat_inode;

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Ben Fennema <bfennema@falcon.csc.calpoly.edu>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>