MFC:	r247859

Update the manual page to reflect reality.  With r138509 and r152355,
"nostrictjoliet" option for mount_cd9660(8) was completely replaced with
"brokenjoliet" somehow.
MFC r247595:

Fix wrong assignment.

Submitted by:	Sascha Wildner <saw online de>
Obtained from:	DragonFly rev 9568dd07a22a136e380e6c19a8ea188eb92976d5
MFC r247596:

Fix assignment of maximum bounadary.

Submitted by:	Sascha Wildner <saw online de>
Obtained from:	DragonFly rev fd39c81ba220f7ad6e4dc9b30d45e828cf58a1ad
MFC r248627:

Don't attempt to reference sc before testing whether it's NULL.

Submitted by:	Sascha Wildner
Obtained from:	DragonFly