os_freebsd.cpp: Fix crash on FreeBSD 9.2 caused by wrong SCSI status check 
condition. Print SCSI debug info on errors only if requested



git-svn-id: https://svn.code.sf.net/p/smartmontools/code/trunk/smartmontools@3858 4ea69e1a-61f1-4043-bf83-b5c94c648137