perf help: Lower levenshtein penality for deleting character

The levenshtein penalty for deleting a character was far higher than
subsituting or inserting a character. Lower the penalty to match that
of inserting a character.

Before:

$ perf recccord
perf: 'recccord' is not a perf-command. See 'perf --help'.
$

After:

$ perf recccord
perf: 'recccord' is not a perf-command. See 'perf --help'.

Did you mean this?
record
$

Signed-off-by: Ian Rogers <[e-mail]>
Tested-by: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/help-unknown-cmd.c

···
 
 	if (main_cmds->cnt) {
 		/* This reuses cmdname->len for similarity index */
-		for (i = 0; i < main_cmds->cnt; ++i)
+		for (i = 0; i < main_cmds->cnt; ++i) {
 			main_cmds->names[i]->len =
-				levenshtein(cmd, main_cmds->names[i]->name, 0, 2, 1, 4);
-
+				levenshtein(cmd, main_cmds->names[i]->name,
+					/*swap_penalty=*/0,
+					/*substition_penality=*/2,
+					/*insertion_penality=*/1,
+					/*deletion_penalty=*/1);
+		}
 		qsort(main_cmds->names, main_cmds->cnt,
 		      sizeof(*main_cmds->names), levenshtein_compare);