Revert "cmdlib: workaround rofiles-fuse mounts leaking"

This reverts commit ba45b29.

Author: HuijingHei

src/cmdlib.sh

@@ -758,8 +758,6 @@ else
 fi
 echo \$rc > ${rc_file}
 if [ -n "\${cachedev}" ]; then
-    # XXX: brutal workaround for https://github.com/coreos/coreos-assembler/issues/3848
-    killall rofiles-fuse || :
     /sbin/fstrim -v ${workdir}/cache
     mount -o remount,ro ${workdir}/cache
     fsfreeze -f ${workdir}/cache