Make the kernel filesystem scriptlets executable

This is so that they can be run from the main Makefile, instead
of having to edit them to put them inside the Makefile.

common/kernfs.xsl

@@ -7,6 +7,8 @@
   <xsl:output method="text"/>
 
   <xsl:template match="/">
+    <xsl:text>#!/bin/bash
+</xsl:text>
     <xsl:apply-templates select="//userinput[contains(string(),'--bind') or
                                              contains(string(),'/proc') or
                                              contains(string(),'readlink') or

common/libs/func_book_parser

@@ -159,9 +159,11 @@ create_kernfs_scripts() {    #
   xsltproc --nonet \
            -o kernfs-scripts/devices.sh kernfs.xsl \
            $BOOK/*/kernfs.xml >> $LOGDIR/$LOG 2>&1
+  chmod +x kernfs-scripts/devices.sh
   xsltproc --nonet \
            -o kernfs-scripts/teardown.sh kernfs.xsl \
            $BOOK/chapter??/reboot.xml >> $LOGDIR/$LOG 2>&1
+  chmod +x kernfs-scripts/teardown.sh
 
   echo "done"