build-cd-image: Always pick the last kernel

Fixes the Debian armhf image.

Signed-off-by: Marc Zyngier <maz@kernel.org>
diff --git a/build-cd-image b/build-cd-image
index 1b058f3..f7c8f3d 100755
--- a/build-cd-image
+++ b/build-cd-image
@@ -7,7 +7,7 @@
 
 mkdir $out
 
-vmlinuzpath=$(xorriso -dev $1 -sh_style_result on -find / -type f -name vmlinuz 2>/dev/null | cut -f2- -d '/')
+vmlinuzpath=$(xorriso -dev $1 -sh_style_result on -find / -type f -name vmlinuz 2>/dev/null | cut -f2- -d '/' | tail -1)
 grubcfgpath=$(xorriso -dev $1 -sh_style_result on -find / -type f -name grub.cfg 2>/dev/null | cut -f2- -d '/' | tail -1)
 
 if [ "$vmlinuzpath" != "" ]; then