dracut.sh: do not copy /var/run and /var/lock from the system

https://bugs.gentoo.org/show_bug.cgi?id=428142

If /var/run and /var/lock are real directories, we would end up with:
var/lock/lock -> /run/lock
var/run/run -> /run

dracut.sh

@@ -810,7 +810,7 @@ if [[ $prefix ]]; then
 fi
 
 if [[ $kernel_only != yes ]]; then
-    for d in usr/bin usr/sbin bin etc lib sbin tmp usr var var/log var/run var/lock $libdirs; do
+    for d in usr/bin usr/sbin bin etc lib sbin tmp usr var var/log $libdirs; do
         [[ -e "${initdir}${prefix}/$d" ]] && continue
         if [ -L "/$d" ]; then
             inst_symlink "/$d" "${prefix}/$d"