dracut-functions: fixed doubled $initdir prefix inst_library()

Commit 172d85b9c9 caused following error:

./dracut-functions: line 307: cd: /tmp/initramfs.mP7cPY/tmp/initramfs.mP7cPY/lib64: No such file or directory

Patch removes beginning $initdir for symlink case.

dracut-functions

@@ -302,8 +302,10 @@ inst_library() {
         lib=${src##*/}
         inst_simple "$reallib" "$reallib"
         inst_dir "${dest%/*}"
-        [[ -L ${initdir}${dest%/*} ]] && \
-        dest=$(readlink -f ${initdir}${dest%/*})/
+        if [[ -L ${initdir}${dest%/*} ]]; then
+            dest=$(readlink -f ${initdir}${dest%/*})/
+            dest=${dest#${initdir}}
+        fi
         (cd "${initdir}${dest%/*}" && ln -s "$reallib" "$lib")
     else
         inst_simple "$src" "$dest"