verification/dot2k: More robust template variables

verification/dot2k: More robust template variables

The dot2k templates currently have variables that are automatically
filled by the script marked as an uppercase VARIABLE. This requires some
care while adding new variables to avoid using valid keywords and get
them unexpectedly substituted.

This patch switches the variables to the %%VARIABLE%% notation to make
the pattern substitution more robust.

Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20241227144752.362911-4-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>