Revert "cmdlib.sh: keep trying to remount after killall hack"

This reverts commit 5e7638f.

src/cmdlib.sh

@@ -762,10 +762,7 @@ if [ -n "\${cachedev}" ]; then
     # XXX: brutal workaround for https://github.com/coreos/coreos-assembler/issues/3848
     killall rofiles-fuse || :
     /sbin/fstrim -v ${workdir}/cache
-    while ! mount -o remount,ro ${workdir}/cache; do
-        echo "failed to remount cache ro; retrying..." |& tee /dev/virtio-ports/cosa-cmdout
-        sleep 1
-    done
+    mount -o remount,ro ${workdir}/cache
     fsfreeze -f ${workdir}/cache
     fsfreeze -u ${workdir}/cache
     umount ${workdir}/cache