Fix several problems in the new iSCSI stack; this includes interoperability
fix for LIO (Linux target), removing possibility for the target to avoid mutual
CHAP by choosing to skip authentication altogether, and fixing truncated error
messages in iscsictl(8) output.  This also fixes several of the problems found
with Coverity.

Note that this change requires world rebuild.

Coverity CID:	1088038, 1087998, 1087990, 1088004, 1088044, 1088041, 1088040
Approved by:	re (blanket)
Sponsored by:	FreeBSD Foundation