p2v: virt-p2v-make-disk: Use a more robust way to get the latest kernel version.

Fedora/i686 does not have a package called 'kernel', so the command
'rpm -q kernel' fails.  In any case the method used wasn't exactly
very robust.

The new method is based on how febootstrap used to do this.

This updates commit d723b352f8.

p2v/virt-p2v-make-disk.in

@@ -113,8 +113,8 @@ EOF
         cat > $tmpdir/post-install <<'EOF'
 #!/bin/bash
 # Rebuild the initramfs.
-version=` rpm -q kernel | sort -rV | head -1 | sed 's/kernel-//' `
-dracut -f --kver $version
+latest_version="$(cd /lib/modules; ls -1vr | head -1)"
+dracut -f --kver $latest_version
 EOF
         # Double quotes because we want $tmpdir to be expanded:
         extra_args="