scripts: Added shortform for -t/--total flag

This flag has proven useful in external scripts, might as well give it a
short form.

-t is also an infrequently used flag, so I think the risk of collision
is low even across all csv scripts. The only existing use is in
test/bench.py for -t/--trace (and apparently in gcov for -t/--stdout?).

scripts/code.py

@@ -1219,7 +1219,7 @@ if __name__ == "__main__":
             action='store_true',
             help="Only show the total.")
     parser.add_argument(
-            '--total',
+            '-t', '--total',
             action='store_true',
             help="Equivalent to --summary + --no-header + --small-total. "
                 "Useful for scripting.")