udf: use crc_itu_t from lib instead of udf_crc

As pointed out by Sergey Vlasov, UDF implements its own version of
the CRC ITU-T V.41.  Convert it to use the one in the library.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Cc: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/udf/Makefile

@@ -6,4 +6,4 @@ obj-$(CONFIG_UDF_FS) += udf.o
 
 udf-objs     := balloc.o dir.o file.o ialloc.o inode.o lowlevel.o namei.o \
 		partition.o super.o truncate.o symlink.o fsync.o \
-		crc.o directory.o misc.o udftime.o unicode.o
+		directory.o misc.o udftime.o unicode.o