Don't try kexec'ing to non-existing amd64 kernel.

config/chroot_local-includes/usr/local/bin/tails-boot-to-kexec

@@ -7,19 +7,19 @@ running_on_amd64_hardware() {
 case "$1" in
    kernel)
       boot_kernel="$2"
-      if running_on_amd64_hardware ; then
-	 echo "$boot_kernel" | sed -e 's,/vmlinuz$,/vmlinuz3,'
-      else
+      # if running_on_amd64_hardware ; then
+      # 	 echo "$boot_kernel" | sed -e 's,/vmlinuz$,/vmlinuz3,'
+      # else
 	 echo "$boot_kernel"
-      fi
+      # fi
       ;;
    initrd)
       boot_initrd="$2"
-      if running_on_amd64_hardware ; then
-	 echo "$boot_initrd" | sed -e 's,/initrd\.img$,/initrd3.img,'
-      else
+      # if running_on_amd64_hardware ; then
+      # 	 echo "$boot_initrd" | sed -e 's,/initrd\.img$,/initrd3.img,'
+      # else
 	 echo "$boot_initrd"
-      fi
+      # fi
       ;;
    *)
       usage "$0 kernel|initrd"