Change the default log level for iSCSI target from 3 to 1.  It should
have been 1 from the beginning; not sure how it ended up at 3.

MFC after:	1 month
Sponsored by:	The FreeBSD Foundation

(cherry picked from commit d83cc4937b8bd9e229be25085cf452dbe05447ec)

Conflicts:
	sys/cam/ctl/ctl_frontend_iscsi.c