UDF: fix UID and GID mount option ignorance

UDF: fix UID and GID mount option ignorance

This patch fix weird behaviour of UDF mounting procedure.  To get UID
changed (for now) we have to type

	mount -t udf -o uid=some_user,uid=ignore /dev/device /mnt/moun_point

and specifying two uid at once is strange a bit.  So with the patch we are
able to mount without additional 'uid=ignore' option.  The same for GID
option is done.

This patch will not break current mount scheme (with two option).

Btw this does fix (I hope) the following

	[BUG 6124] mount of UDF fs ignores UID and GID options
        http://bugzilla.kernel.org/show_bug.cgi?id=6124

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Michael <auslands-kv@gmx.de>
Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>