Bug#947811: systemd: don't check *mounted* filesystems by default

[Joshua Hudson]

#need_real_mtab
/dev/mapper/isw_cfbejbfeib_Volume11 / ext3 defaults 0 1
/dev/mapper/isw_cfbejbfeib_Volume12 none swap sw 0 0
none /tmp tmpfs defaults 0 0
/dev/mapper/isw_cfbejbfeib_Volume13 /home ext3 defaults 0 2
/dev/mapper/isw_cfbejbfeib_Volume14 /home/joshua/imagefiles ext3 defaults 0 3
/dev/sr0 /media/cdrom iso9660 noauto,ro,user 0 0
/dev/sr1 /media/cdrom1 iso9660 noauto,ro,user 0 0