Before the recent loader changes, the root device to use for CD-ROM
booting (/dev/cd0) was properly passed from the loader to the kernel
so the entry in fstab was never used.
However, with the new loader code this doesn't happen anymore (for
yet unknown reasons), so the fstab entry is tried and fails, because
it is wrong.
So for now, adjust our fstabs to use /dev/cd0.
#
# Device Mountpoint FStype Options Dump Pass#
-/dev/acd0a / cd9660 ro,noauto 0 0
+/dev/cd0 / cd9660 ro,noauto 0 0
swap /root mfs rw,-C,-s=32768 0 0
swap /var mfs rw,-C,-s=262144,-i=4096 0 0
swap /tmp mfs rw,-C,-s=16384 0 0
#
# Device Mountpoint FStype Options Dump Pass#
-/dev/acd0a / cd9660 ro,noauto 0 0
+/dev/cd0 / cd9660 ro,noauto 0 0
swap /root mfs rw,-C,-s=8192 0 0
swap /var mfs rw,-C,-s=12288 0 0
swap /tmp mfs rw,-C,-s=8192 0 0