Minor (destroy) fixes.

beadm

@@ -28,7 +28,7 @@ PATH=${PATH}:/bin:/usr/bin:/sbin:/usr/sbin
 
 if [ $( uname -r | cut -d '.' -f1 ) -lt 8 ]
 then
-  echo "ERROR: beadm only works on FreeBSD 8.0 or later."
+  echo "ERROR: beadm only works on FreeBSD 8.0 or later"
 fi
 
 __usage() {
@@ -276,7 +276,7 @@ EOF
           fi
         else
           ORIGINS=$( zfs list -r -H -o origin ${POOL}/ROOT/${2} )
-          if zfs destroy ${POOL}/ROOT/${2} 1> /dev/null 2> /dev/null
+          if ! zfs destroy ${POOL}/ROOT/${2} 1> /dev/null 2> /dev/null
           then
             zfs destroy -r ${POOL}/ROOT/${2} 2>&1 \
               | grep "${POOL}/ROOT/" \
@@ -286,12 +286,15 @@ EOF
                   zfs promote ${I} 2> /dev/null
                 done
           fi
+          if ! [ "${ORIGINS}" = "-" ]
+          then
             echo "${ORIGINS}" \
               | while read I
                 do
                   zfs destroy -r ${I} 2> /dev/null
                 done
           fi
+        fi
         echo "Destroyed successfully"
         ;;
       (*)