uvol: unbreak build and adapt to updated ucode

uvol: unbreak build and adapt to updated ucode

 * Fix build which was broken by a wrong path in the Makefile.

Adapt to ucode commit 4618807 ("main: rework CLI frontend"):
 * ucode now no longer needs the {% %} around each code file, remove
   that and safe one level of indentation.
 * ARGV now no longer includes ucode executable and script itself

Fixes: 6350c7bc6 ("uvol: replace with re-write in ucode")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>