scripts: Relaxed -C/--compare to match eagerly

I.e. zip_longest -> zip

This is for better consistency with other scripts where we treat
shortened names as equivalent to being padded with globs.

Padding with globs is slightly more flexible, and is convenient when
scripts append special fields that the user may not expect (x/y after
defines in plot.py/plotmpl.py for example).

The alternative behavior of rejecting longer-than-expected names isn't
super useful.

scripts/data.py

@@ -650,8 +650,7 @@ def table(Result, results, diff_results=None, *,
         compare_ = min(
             (n for n in table.keys()
                 if all(fnmatch.fnmatchcase(k, c)
-                    for k, c in it.zip_longest(n.split(','), compare,
-                        fillvalue=''))),
+                    for k, c in zip(n.split(','), compare))),
             default=compare)
         compare_r = table.get(compare_)